JP2008120591A - Sheet conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for preventing documents placed in a document placing portion from being disturbed by a document projecting from an opening part in a document conveying device capable of conveying the document for double-side reading. <P>SOLUTION: An ADF 3 conveys the document Gm in order of a first route, a second route and a third route. In the first and the second routes, the document Gm is conveyed for switch-back in a double-way path 39, and delivered in the third route without switch-back conveyance. A separating roller 34 is provided downstream of a paper feeding tray 30, and a second front sensor 53 is arranged downstream of the separating roller 53. A plurality of conveying rollers 35A-35D are arranged in a document conveyance path 32. Driving force of a motor 67 is transmitted to the conveying rollers 35A-35D and the separating roller 34 through a first gear system 70 and a third gear system 120. A control section 60 switches a motor 60 from CW rotation to CCW rotation when the second front sensor 53 detects a rear end of the document Gm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, a first tray for placing a sheet member before feeding, a second tray for placing a sheet member after discharge, and an opening provided on the upper side of the first tray are connected via a reading position. The present invention relates to a sheet conveying apparatus having a conveying path.

  2. Description of the Related Art Conventionally, there is known an image reading apparatus provided with a document conveying device called ADF (Auto Document Feeder) that conveys a document from a paper feed tray to a paper discharge tray through a conveyance path. Also, there is provided a document conveying device that performs conveyance for reading both sides of a document by reversing the leading edge and the trailing edge of the document during conveyance in order to read a document printed on both sides of the first surface and the second surface. It is known (see, for example, Patent Document 1).

  FIG. 33 and FIG. 34 are schematic diagrams showing a conveyance path of a conventional document conveying apparatus for double-sided reading. As shown in FIG. 33, a document is placed on the sheet feed tray 100 with the first side (first page) facing upward. The original P is fed to the conveyance path 102 by the paper feed roller 101. A transport roller 103 is appropriately provided in the transport path 102. The original is conveyed to the conveyance roller 103, and when the original passes through the reading position X, the first surface of the original P is read by the image reader. When the sensor detects the trailing edge of the document P after the first surface is read, the paper discharge roller 104 stops with the trailing edge of the document nipped.

  As shown in FIG. 34, the paper discharge roller 104 reverses and conveys the original P to the return path 105. The original P again enters the upstream side in the conveyance direction of the reading position X on the conveyance path 102 from the return path 105. Then, when the document P conveyed by the conveying roller 103 passes the reading position X, the second surface (second page) is read by the image reader. After the second surface is read, when the sensor detects the trailing edge of the document P, the paper discharge roller 104 stops again with the vicinity of the trailing edge of the document being nipped. Thereafter, the paper discharge roller 104 reverses and conveys the original P to the switchback path 105. The document P that has entered the conveyance path 102 again from the return path 105 passes through the first surface in a normal state facing the reading position X. The original P is transported through the transport path 102 and discharged onto the paper discharge tray 106 with the first surface facing downward. As a result, the originals are discharged to the discharge tray 106 in the order in which they are stacked on the paper feed tray 100.

  As another form of the conventional document conveying apparatus capable of reading both sides, the return path 105 is extended from the upper portion of the substantially U-shaped conveying path 102 in the lateral direction, and the end of the return path 105 is set to the sheet feeding tray 100. The thing opened to the outside of the apparatus toward the upper side of this is proposed (refer patent document 2).

JP-A-8-85649 Japanese Patent Laid-Open No. 11-157756

  In the transport path that extends the return path 105 toward the upper side of the paper feed tray 100, a part of the document P protruding from the return path 105 may come into contact with the document P placed on the paper feed tray 100. . As a result, the document P placed on the paper feed tray 100 is disturbed, and there is a possibility that a paper feed failure from the paper feed tray 100 to the transport path 102 may occur.

  The present invention has been made in view of such circumstances, and in a sheet conveying apparatus that conveys a sheet-like sheet member such as a document, the sheet member is placed on the tray by the sheet member protruding from the tray on which the sheet member is placed. Another object of the present invention is to provide a means for preventing another sheet member from being disturbed.

  (1) The present invention is applied to a sheet conveying apparatus that conveys a sheet-like sheet member. The sheet conveying apparatus includes a first tray, a second tray, an opening, a sheet conveying path, a feeding unit, a sheet conveying unit, a driving source, a control unit, a transmitting unit, and a first detection. Means.

  The first tray places a plurality of sheet members before feeding. The second tray places a plurality of discharged sheet members. The opening is provided on the upper side of the first tray. The sheet conveyance path connects the first tray, the second tray, and the opening through a reading position.

  A feeding unit is provided in the sheet conveyance path. The feeding means presses the sheet member placed on the first tray and sequentially feeds the sheet member to the sheet conveying path. The sheet conveying means is provided in the sheet conveying path. The sheet member is conveyed by the sheet conveying means.

  A typical driving source is an electric motor or the like, which is rotationally driven in either the forward rotation direction or the reverse rotation direction. The control means switches the rotation direction of the drive source to either the normal rotation direction or the reverse rotation direction.

  A transmission means is connected to the drive source. The transmission unit transmits a rotational driving force corresponding to the position of the sheet member in the sheet conveyance path from the driving source to the sheet conveyance unit. Further, when the driving source is driven in the forward rotation direction, a rotational driving force is transmitted from the driving source to the feeding means, and when the driving source is driven in the reverse rotation direction, the feeding means is supplied from the driving source. The transmission of the rotational driving force to is cut off.

  The first detection means is provided on the downstream side in the transport direction from the feeding means in the first transport path. The first detection means detects the rear end of the sheet member conveyed along the first conveyance path.

  In the sheet conveying apparatus according to the present invention, a plurality of sheet members are sequentially conveyed through the following first path, second path, and third path, so that the sheet members are moved from the first tray to the second tray. It is conveyed one by one. Here, the first path is a path in which the sheet member fed from the first tray returns to the sheet conveyance path upstream in the conveyance direction from the reading position after passing the reading position. The second path is a path through which the sheet member returned to the sheet conveyance path returns to the sheet conveyance path on the upstream side in the conveyance direction from the reading position via the reading position and the opening. The third path is a path through which the sheet member returned to the sheet conveyance path is discharged to the second tray through the reading position and the opening.

  In the case where the sheet member is conveyed from the first tray to the second tray sequentially through the first path, the second path, and the third path, the control unit is configured to convey the sheet member along the first path. The drive source is switched from the normal rotation direction to the reverse rotation direction based on the detection result of the rear end of the sheet member by the first detection means.

  In the sheet conveying apparatus configured as described above, when the driving source is driven in the forward rotation direction, the sheet member on the first tray is fed to the sheet conveying path by the feeding unit. The sheet member is first returned to the sheet conveyance path again through the first path. When the sheet member is conveyed along the first path, the rotation direction of the drive source is switched based on the detection result of the first detection unit. For example, when the rear end of the sheet member is detected by the first detection means, the rotation direction of the drive source is switched from the current normal rotation direction to the reverse rotation direction. The first detection means is disposed downstream in the transport direction from the feeding means. Therefore, the drive source is rotationally driven in the forward rotation direction until the first detection means detects the rear end of the sheet member. Therefore, the subsequent sheet member placed on the first tray receives the rotational driving force of the drive source until the rear end of the previously conveyed sheet member is detected by the first detection means. It is pressed by the feeding means. Thereby, even if the sheet member is exposed to the outside from the opening in the conveyance process and contacts the sheet member before feeding placed on the first tray, the sheet member on the first tray is not disturbed, The alignment state is maintained.

  The sheet member returned to the sheet conveyance path again through the first path is discharged to the second tray after passing through the second path and the third path. In this case, an image reading process is performed during the conveyance process of the sheet member. Therefore, the drive source is switched from the normal rotation direction to the reverse rotation direction before the leading edge of the sheet member reaches the reading position in order to prevent quality degradation of the read image. Even when the sheet member is conveyed through the second path, the sheet member comes into contact again with the sheet member before feeding on the first tray, but the pressure contact of the sheet member by the feeding unit is continued. The alignment state of the sheet members on the first tray is maintained.

  As the sheet members are conveyed through the first path, the second path, and the third path, the stacking order of the sheet members discharged to the second tray matches the stacking order when the sheets are loaded on the first tray. Is done.

  (2) In this case, when the sheet member is conveyed along the first path, the control unit moves the drive source from the normal rotation direction on condition that the first detection unit detects the rear end of the sheet member. It is preferable to switch to the reverse rotation direction.

  (3) The sheet conveying path extends from the first tray through the reading position to the second tray, and from the predetermined first position downstream in the conveying direction from the reading position to the opening. It is preferable that the sheet conveying unit includes a first conveying unit provided in the first conveying path and a second conveying unit provided in the second conveying path. .

  (4) When the control unit conveys the sheet member along the second path, the leading end of the sheet member is located downstream of the first detection unit in the conveyance direction and upstream of the first position in the conveyance direction. The drive source is switched from the normal rotation direction to the reverse rotation direction on condition that the second position is reached.

  Thereby, conveyance of the sheet | seat member in a 2nd path | route is performed suitably.

  (5) The first detection means is provided in the first transport path. A leading end and a trailing end of a sheet member that is provided on the downstream side in the transport direction from the first detection unit in the first transport path and on the upstream side in the transport direction from the reading position are detected. In the case where the second detection means is further provided, it is desirable that the second position is downstream in the transport direction from the first detection means and upstream in the transport direction from the second detection means.

  (6) In the first conveyance path, when the section distance from the feeding unit to the second position is shorter than the minimum conveyance direction length of the sheet member that can be conveyed on both sides by the apparatus in the first conveyance path. Is preferable.

  (7) The feeding unit includes a roller body that rotates by receiving the rotational driving force transmitted from the transmission unit, and a plate that is pressed against the roller body. In such a configuration, the present invention is suitable.

  (8) The first detection means is provided in proximity to the feeding means.

  Thereby, the sheet member fed to the sheet conveyance path can be detected at an early stage.

  (9) The transmission means is mounted on the first tray and a first transmission mechanism for transmitting a rotational driving force in a fixed direction from the driving source to the first conveying means regardless of the rotation direction of the driving source. In the course of transporting one sheet member, the rotation direction of the drive source is first switched from the normal rotation direction to the reverse rotation direction by the control means from the feeding operation of feeding the sheet member to the first conveyance path. And a second transmission mechanism for transmitting a rotational driving force from the driving source to the feeding means.

  With such a transmission means, the state in which the sheet member waiting on the first tray after the sheet member is fed from the first tray is pressed by the feeding means until the next sheet member is fed. Maintained.

  (10) The sheet conveying apparatus according to the present invention is provided on the opening side from the first position in the second conveying path and on the first position side from the second conveying means, and the second conveying path. Third detection means for detecting the rear end of the conveyed sheet member, and first driving force supply means for supplying the second conveying means with rotational driving force for switchback conveying the sheet member in the second conveying path May be further provided.

  Thereby, the switchback conveyance of the sheet member in the second conveyance path is accurately performed.

  (11) The rotation direction of the second transport unit is switched to a direction corresponding to the rotation direction of the first drive supply unit that is controlled based on the detection result of the third detection unit.

  Thereby, the conveyance of the sheet member in the second conveyance path is smoothly performed.

  (12) In the sheet conveying apparatus according to the present invention, the first driving force supply unit includes the driving source and the transmission unit. The second transport means is connected to the transmission means. The rotation direction of the second transport unit is switched to a direction corresponding to the rotation direction of the drive source based on the detection result of the third detection unit.

  Even with such a configuration, smooth conveyance of the sheet member is realized.

  (13) The second transport unit transports the sheet member in the second transport path in a direction to return the first transport path from the opening side to the first transport path when the drive source rotates in the forward rotation direction, and drives the drive When the source rotates in the reverse rotation direction, the sheet member in the second conveyance path is conveyed to the opening side.

  (14) The sheet conveying apparatus according to the present invention is rotatably supported at the first position, and the sheet member conveyed along the first conveying path is either the second conveying path side or the second tray side. And a second driving force supply means for supplying a rotational driving force to the guiding means.

  Thereby, the sheet member is easily branched at the first position.

  (15) It is preferable that the rotation position of the guide means is switched by the second driving force supply means controlled according to the first path to the third path.

  (16) The second driving force supply means includes the driving source and the transmission means, and the guide means is connected to the transmission means, and the driving source rotates in the forward rotation direction. The sheet member may be guided to the second tray side, and the sheet member may be guided to the second conveyance path side when the driving source rotates in the reverse rotation direction.

  (17) The present invention includes a sheet feeding port for feeding a sheet member, a sheet discharge port for discharging the sheet member, a conveying member for conveying the sheet member from the sheet feeding port to the sheet discharge port, and the sheet feeding port. A first path for guiding the sheet member while being conveyed from the end to the end located above the paper feed port, and a sheet member while being conveyed from the end to the end through the reading position again A sheet conveying apparatus comprising: a second path for guiding; and a third path for guiding the sheet member while being conveyed from the terminal end to the discharge port through the reading position, and a reversible drive source And a transmission member that rotates the conveying unit according to the normal rotation of the driving source and stops the rotation of the conveying unit according to the reverse rotation of the driving source, and a downstream of the sheet feeding port in the first path. First detection means provided on the side, and the first path Based on that over preparative member rear end is detected, and control means for switching the reversing said driving source from the forward rotation, it may be regarded as a sheet conveying apparatus having a.

  (18) In this case, an image reader is provided at the reading position, and the document conveyed on the first path passes through the reading position without being read by the image reader. Is preferred.

  According to the present invention, when the sheet member is conveyed along the first path and the second path, the sheet member is exposed from the opening, and the sheet member becomes the sheet member before feeding on the first tray. Even in the case of contact, the alignment state of the sheet members on the first tray is not disturbed. Accordingly, the subsequent sheet member can be reliably and quickly fed to the sheet conveyance path.

  Embodiments of the present invention will be described below with reference to the drawings as appropriate. In addition, this embodiment is only an example which actualized this invention, and it cannot be overemphasized that embodiment can be changed suitably in the range which does not change the summary of this invention.

  FIG. 1 shows an external configuration of an image reading apparatus 1 according to an embodiment of the present invention, and FIG. 2 shows a main internal configuration of the image reading apparatus 1. The image reading apparatus 1 is, for example, a copy machine, a facsimile machine, a scanner, or a multi-function device (MFD: Multi Function Device) integrated with a copy function, a facsimile function, a scanner function, etc. This is realized as an image reading unit for reading an image (corresponding to a sheet member).

  As shown in FIGS. 1 and 2, the image reading apparatus 1 includes a document cover 4 that includes a document table 2 that functions as an FBS (Flatbed Scanner) and an ADF (Auto Document Feeder) 3 that is an automatic document transport mechanism. Have The ADF 3 is an example of the sheet conveying apparatus of the present invention.

  An operation panel 5 is provided on the front side of the document table 2. The operation panel 5 includes various operation keys 11 and a liquid crystal display unit 12. The user inputs a desired command using the operation panel 5. For example, the operation key 11 is used to input “start” indicating start or resumption of reading of a document and “stop” indicating stop or interruption of reading. The image reading apparatus 1 receives these predetermined inputs and performs an operation according to the inputs. The image reading apparatus 1 is operated not only by a command input from the operation panel 5 but also by a command connected to the computer and transmitted from the computer via a printer driver, a scanner driver, or the like.

  As shown in FIG. 2, the platen glass 20, 21 is disposed on the top surface of the document table 2 that faces the document cover 4. When the document cover 4 is opened, the platen glasses 20 and 21 are exposed as the upper surface of the document table 2. When the document cover 4 is closed, the entire upper surface of the document table 2 including the platen glasses 20 and 21 is covered. An image reading unit 22 (image reading means) is provided inside the document placing table 2 so as to face the platen glasses 20 and 21.

  The platen glass 20 is used to place a document when the image reading apparatus 1 is used as an FBS, and is made of, for example, a transparent glass plate. An opening for exposing the platen glass 20 is formed at the center of the upper surface of the document placing table 2, and an area of the platen glass 20 exposed from the opening becomes an original reading area in the FBS.

  The platen glass 21 constitutes a reading position when the ADF 3 of the image reading apparatus 1 is used, and is made of, for example, a transparent glass plate. An opening is formed at the reading position of the document table 2. The platen glass 21 is exposed from this opening. The platen glass 21 is rectangular in plan view.

  A positioning member 23 is interposed between the platen glass 20 and the platen glass 21. The positioning member 23 is a flat plate-like member that is long in the main scanning direction. The positioning member 23 is used as a document positioning reference when a document is placed on the platen glass 20 which is a document placement surface in the FBS. Therefore, on the upper surface of the positioning member 23, a display indicating the center position and both end positions of various document sizes such as A4 size and B5 size is written. On the upper surface of the positioning member 23, a guide surface is formed that captures and deflects the document passing over the platen glass 21 by the ADF 3 and returns it to the ADF 3.

  The image reading unit 22 irradiates the original with light from the light source through the platen glasses 20 and 21, and condenses the reflected light from the original on the light receiving element by the lens and converts it into an electric signal (image sensor). As the image reading unit 22, for example, a close contact type CIS (Contact Image Sensor) image sensor, a reduction optical system CCD (Charge Coupled Device) image sensor, or the like can be used. The image reading unit 22 is provided so as to be capable of reciprocating below the platen glasses 20 and 21 by a carriage motor and a belt driving mechanism which is a scanning mechanism.

  The document cover 4 is provided with a paper discharge tray 31 (the first transport path of the present invention) from a paper feed tray 30 (an example of the first tray of the present invention) through a document transport path 32 (an example of the sheet transport path and the first transport path of the present invention). An ADF 3 that continuously conveys a document to an example of two trays is provided. In the conveyance process by the ADF 3, the document passes through the reading position on the platen glass 21, and the image reading unit 22 waiting under the platen glass 21 reads the image of the document.

  As shown in FIGS. 1 and 2, the document cover 4 is provided with a paper feed tray 30 and a paper discharge tray 31 in two upper and lower stages with the paper feed tray 30 as an upper side. In the present embodiment, the paper feed tray 30 is disposed above, but the paper discharge tray 31 may be disposed on the paper feed tray 30. A document transported by the ADF 3 is placed on the paper feed tray 30. A plurality of originals are placed on the paper feed tray 30 so that the leading end in the conveyance direction is inserted into the original conveyance path 32 in a stacked state with the first surface facing upward. As shown in FIG. 1, the protective wall 26 is formed by bending the back side of the apparatus of the paper feed tray 30 downward. The lower end of the protective wall 26 is connected to the upper surface of the document cover 4. The protective wall 26 prevents the document on the paper discharge tray 31 from falling when the document cover 4 is opened with respect to the document table 2. A notch 27 is formed in a part of the casing of the ADF 3 below the front side of the sheet feeding tray 30. The cutout 27 enhances the visibility of the document discharged from the discharge tray 31 from the front side of the apparatus. In particular, a small document is difficult to be visually recognized by the paper feed tray 30, but the space between the paper feed tray 30 and the paper discharge tray 31 is expanded by the notch 27, so that the visibility of the small document is enhanced.

  A plurality of documents discharged from the ADF 3 are placed on the discharge tray 31. The paper discharge tray 31 is located at the lower side of the paper feed tray 30 in the vertical direction, and is integrally formed on the upper surface of the document cover 4. The document discharged from the ADF 3 is stacked on the sheet discharge tray 31 with the first side facing down while being separated from the document on the sheet feed tray 30. Both side portions 28 of the paper discharge tray 31 on the front side and the back side of the apparatus have slopes that bulge upward toward the respective sides. The both side portions 28 allow the originals to be slid along the slopes of the both side portions 28 so that the originals are pushed out from above when the originals discharged to the paper discharge tray 31 are taken out. It is easy to take out the document from the tray 31.

  As shown in FIG. 2, a document conveyance path 32 that connects the paper feed tray 30 and the paper discharge tray 31 through a reading position on the platen glass 21 is formed inside the ADF 3. The document conveyance path 32 is formed in a substantially C shape in a sectional view. The document transport path 32 is continuously formed as a passage having a predetermined width through which a document can pass by members, guide plates, guide ribs, and the like constituting the ADF main body.

  The document transport path 32 extends from the paper feed tray 30 to one end side (the left side in the figure) of the document cover 4 and is then curved so as to be reversed downward to reach the reading position on the platen glass 21. A longitudinal sectional view extending from the sheet toward the sheet discharge tray 31 is substantially C-shaped. The document transport path 32 includes three parts: an upper part 32A and a lower part 32C, and a curved part 32B that connects the upper part 32A and the lower part 32C.

  In the document transport path 32, transport means for transporting documents from the paper feed tray 30 to the paper discharge tray 31 is disposed. Specifically, as shown in FIG. 2, a pickup roller 33, a separation roller 34 (an example of the roller body of the present invention), a conveyance roller 35A, 35B, 35C, and 35D, and a paper discharge roller, which are provided in the document conveyance path 32, respectively. A conveying means is constituted by 36 and a pinch roller 37 that is in pressure contact therewith. A driving force is transmitted from the single motor 67 (an example of the driving source of the present invention, see FIG. 6) to each roller constituting the conveying means via a driving force transmitting mechanism described later. Of the transport means, the transport rollers 35A, 35B, 35C, 35D, the paper discharge roller 36, and the pinch roller 37 that presses against them correspond to the first transport means of the present invention.

  As shown in FIG. 2, a pickup roller 33 and a separation roller 34 are provided in the vicinity of the paper feed port of the document conveyance path 32. The pickup roller 33 is rotatably provided at a distal end portion of an arm 29 that is pivotally supported on a shaft 111 (see FIG. 12) that pivotally supports the separation roller 34. The separation roller 34 is provided at a position separated from the pickup roller 33 in the transport direction. The separation roller 34 is rotatably provided so as to be in contact with a guide plate 19 (an example of the plate of the present invention) that is an opposing surface of the document conveyance path 32. The pickup roller 33 and the separation roller 34 are driven to rotate by receiving a driving force from a motor 67 (see FIG. 6). The arm 29 is also moved up and down by the driving force transmitted from the motor 67. The pickup roller 33 and the separation roller 34 have the same diameter and are rotated at the same peripheral speed. The guide plate 19 is provided with a friction pad made of cork or the like at a position facing the separation roller 34. The friction pad separates the uppermost document from a plurality of document bundles by friction generated when the friction pad comes into pressure contact with the roller surface of the rotating separation roller 34. The separation roller 34 and the guide plate 19 realize the feeding unit of the present invention.

  The conveyance rollers 35A, 35B, 35C, and 35D are disposed at different positions on the document conveyance path 32, respectively. In the present embodiment, a transport roller 35A is disposed in the vicinity of the separation roller 34 on the downstream side in the transport direction. A conveyance roller 35 </ b> B is disposed on the upper portion 32 </ b> A of the document conveyance path 32. A conveyance roller 35C is disposed in the lower portion 32C of the document conveyance path 32 and in the vicinity of the reading position upstream in the conveyance direction. A conveyance roller 35D is disposed in the lower portion 32C of the document conveyance path 32 and in the vicinity of the reading position on the downstream side in the conveyance direction. This arrangement is an example, and the number and arrangement of the transport rollers 35A, 35B, 35C, and 35D can be changed as appropriate.

  A pinch roller 37 is provided at a position facing each of the transport rollers 35A, 35B, 35C, and 35D. The shaft of each pinch roller 37 is pressed against the roller surface of each transport roller 35 by being elastically biased by a spring. If each conveyance roller 35A, 35B, 35C, 35D rotates, it will follow and the pinch roller 37 will also rotate. Each pinch roller 37 presses the document against each of the transport rollers 35A, 35B, 35C, and 35D, and the rotational force of each of the transport rollers 35A, 35B, 35C, and 35D is transmitted to the document.

  The paper discharge roller 36 is disposed in the vicinity of the paper discharge port of the document conveyance path 32, and rotates by receiving a driving force from a motor 67 (see FIG. 6). A pinch roller 37 is also provided at a position facing the paper discharge roller 36, and the pinch roller 37 is elastically biased by a spring.

  A two-way path 39 (an example of the sheet conveyance path and the second conveyance path of the present invention) is connected to the lower portion 32C of the document conveyance path 32. The two-way path 39 is downstream of the reading position in the transport direction, more specifically, a connecting position 38 (corresponding to a predetermined first position of the present invention) downstream of the transport roller 35D of the lower portion 32C in the transport direction. It is connected to. In the two-way path 39, when performing double-sided reading, a document whose first surface is read at the reading position is reversed from the downstream side in the conveyance direction to the upstream side in the conveyance direction by reversing the leading edge and the trailing edge. This is for resending to the path 32. The two-way path 39 extends obliquely upward from the connection position 38 toward the upper side of the paper feed tray 30 and intersects the upper portion 32 </ b> A of the document conveyance path 32. The document transported by the switchback is returned to the document transport path 32 from the intersection position 40 between the upper portion 32A and the two-way path 39.

  The end 41 of the two-way path 39 is opened on the upper surface of the ADF 3. A document support section 42 is formed on the paper feed tray 30 side from the end 41 of the two-way path 39 so as to continue from the end 41. The document support portion 42 is for supporting a document protruding from the end 41 of the two-way path 39. The document support section 42 is formed above the paper feed roller 33 and the separation roller 34 and forms the upper cover 6 (see FIG. 1) of the ADF 3. The upper cover 6 is formed so as to cover the entire ADF 3 including the paper feed roller 33 and the separation roller 34, and is configured to be openable and closable around a fulcrum with respect to the housing of the ADF 3. The document support portion 42 configured as the upper cover 6 extends from the terminal end 41 toward the paper feed tray 30 side to reach the upstream side in the transport direction from the paper feed roller 33. As a result, the document protruding outward from the terminal end 41 is supported on the document support portion 41. It does not hang down downstream in the transport direction (left side in FIG. 2) from the paper feed position of the documents stacked on the paper feed tray 30. Documents on the feed tray are not disturbed. Further, when the upper cover 6 is opened around the fulcrum, a part of the document conveyance path 32 and the two-way path 39 in the ADF 3 is exposed, and maintenance work such as jam processing can be performed.

  As shown in FIG. 2, a reversible roller 43 is disposed near the end of the two-way path 39. The reversible roller 43 is rotationally driven in both directions by receiving a driving force from a motor 67 (see FIG. 6). A pinch roller 44 is provided facing the reversible roller 43. The pinch roller 44 is pressed against the roller surface of the reversible roller 43 by elastically urging the shaft with a spring. The pinch roller 44 rotates following the rotation of the reversible roller 43. The original is conveyed by being nipped between the reversible roller 43 and the pinch roller 44. The reversible roller 43 and the pinch roller 44 realize the sheet conveying means and the second conveying means of the present invention that switchback conveys the document.

  FIG. 3 is an enlarged view showing a configuration near the intersection position 40. As shown in FIGS. 2 and 3, a guide flap 46 and a guide flap 47 are disposed at the intersection position 40. The guide flap 46 rotates within a predetermined range with a shaft 48 provided at a corner (lower left side in FIG. 3) between the reading position side of the document conveying path 32 and the connecting position 38 side of the two-way path 39 at the intersection position 40. It is arranged to be movable. The guide flap 46 is a flat plate, and its tip protrudes to the intersection position 40. In FIG. 3, only one guide flap 46 is shown, but a plurality of guide flaps 46 of the same shape are provided at predetermined intervals in the width direction of the document conveying path 32, and the plurality of guide flaps 46 are shafts 48. It is rotated integrally around the center.

  The guide flap 46 rotates about a shaft 48 to rotate to a third position indicated by a solid line in FIG. 3 and a fourth position indicated by a two-dot chain line. The guide flap 46 rotates, for example, from the third position to the lower side in FIG. 3 by coming into contact with the guide member of the document conveyance path 32 or the two-way path 39 and from the fourth position in FIG. The upper side is restricted from rotating. When the guide flap 46 is in the third position, the conveyance path from the paper feed tray 30 side (right side in FIG. 3) to the reading position side (left side in FIG. 3) continues. Further, the conveyance path from the document conveyance path 32 to the connection position 38 side (the lower side in FIG. 3) of the two-way path 39 is closed. As a result, the document that has reached the crossing position 40 from the paper feed tray 30 side of the document conveyance path 32 is allowed to enter the reading position side of the document conveyance path 32, and to the connection position 38 side of the two-way path 39. Entering is stopped. Further, a document that has reached the intersection position 40 from the end 41 side (upper side in FIG. 3) of the two-way path 39 is allowed to enter the reading position side of the document conveyance path 32, and the connection position 38 of the two-way path 39. Entry to the side is prevented.

  When the guide flap 46 is in the fourth position, the conveyance path from the connection position 38 side to the terminal end 41 side of the two-way path 39 is connected, and the reading position of the document conveyance path 32 from the connection position 38 side of the two-way path 39. The transport path to the side is closed. As a result, the document that has reached the crossing position 40 from the connection position 38 side of the two-way path 39 is allowed to enter the terminal end 41 side of the two-way path 39 and enters the reading position side of the document transport path 32. It is prevented.

  The guide flap 46 is rotated by the contact of the front end of the document. The guide flap 46 is in the third position indicated by a solid line in FIG. 3 due to its own weight or under the urging force of an elastic member such as a spring. When the leading edge of the document conveyed from the coupling position 38 toward the intersection position 40 abuts on the guide flap 46, the guide flap 46 rotates upward in FIG. 3, and the fourth dotted line shown in FIG. Become position. The leading edge of the document conveyed from the end 41 side of the two-way path 39 to the intersection position 40 contacts the guide flap 46. Since the guide flap 46 is restricted from rotating from the third position to the fourth position, the document is guided to the guide flap 46. . The shape of the guide flap 46 is easy to rotate due to the contact of the leading edge of the document conveyed from the connection position 38 side to the intersection position 40, and the document conveyed from the terminal end 41 side of the two-way path 39 to the intersection position 40 is conveyed. A shape that is easily guided to the reading position side of the path 32 is employed.

  The guide flap 47 has a predetermined range around a shaft 49 provided at a corner (upper right side in FIG. 3) between the paper feed tray 30 side of the document conveyance path 32 and the end 41 side of the two-way path 39 at the intersection position 40. It is arrange | positioned so that rotation is possible. The guide flap 47 is a wing-shaped flat plate, and its tip protrudes to the intersection position 40. Although only one guide flap 47 is shown in FIG. 3, a plurality of guide flaps 47 having the same shape are provided at predetermined intervals in the width direction of the document conveying path 32. The plurality of guide flaps 47 are rotated together.

  The guide flap 47 moves around the shaft 49 to move to a fifth position indicated by a solid line in FIG. 3 and a sixth position indicated by a two-dot chain line. The guide flap 47 rotates from the fifth position to the right side in FIG. 3 by abutting against the guide member of the document conveyance path 32 or the two-way path 39, and from the sixth position to the upper side in FIG. Rotation is restricted. When the guide flap 47 is in the fifth position, the conveyance path from the end 41 side of the two-way path 39 to the reading position side of the document conveyance path 32 continues. Further, the conveyance path from the connection position 38 side of the two-way path 39 to the paper feed tray 30 side of the document conveyance path 32 is closed.

  When the guide flap 47 is in the sixth position, the conveyance path from the paper feed tray 30 side to the reading position side of the document conveyance path 32 continues, and a two-way path from the paper feed tray 30 side of the document conveyance path 32. The conveyance path to the end 41 side of 39 is closed. As a result, the document that has reached the intersection position 40 from the paper feed tray 30 side of the document transport path 32 is allowed to enter the reading position side of the document transport path 32 and enters the end 41 side of the two-way path 39. To be stopped.

  Switching of the conveyance path by the guide flap 47 is performed by contacting the original. The guide flap 47 is in the fifth position indicated by a solid line in FIG. 3 due to its own weight or under the urging force of an elastic member such as a spring. When the document conveyed from the sheet feeding tray 30 side of the document conveyance path 32 contacts the guide flap 47, the guide flap 47 rotates to the left in FIG. 3, and the sixth dotted line shown in FIG. Become position. Even if the leading edge of the document conveyed from the coupling position 38 side to the intersection position 40 abuts on the guide flap 47, the document is guided by the guide flap 47 and enters the end 41 side of the two-way path 39. To do. The wing shape of the guide flap 47 is easy to rotate due to the contact of the document conveyed from the paper feed tray 30 side of the document conveyance path 32 to the intersection position 40, and from the connection position 38 side of the two-way path 39 to the intersection position 40. A shape in which the conveyed document is easily guided to the end 41 side of the two-way path 39 is employed.

  FIG. 4 is an enlarged view showing a configuration in the vicinity of the connection position 38. As shown in FIGS. 2 and 4, a guide flap 50 (an example of guide means of the present invention) is disposed at the connection position 38. The guide flap 50 is disposed so as to be rotatable about a shaft 51. When the driving force is transmitted from the motor 67 (see FIG. 6) to the guide flap 50, the guide flap 50 is rotated to either the first position indicated by the solid line or the second position indicated by the two-dot chain line in FIG. Is done. The guide flap 50 is switched to either the two-way path 39 side or the document conveyance path 32 side following the paper discharge tray 31. The guide flap 50 rotates from the first position to the upper side in FIG. 4 by abutting against the guide member of the document conveyance path 32 or the two-way path 39, and from the second position to the lower side in FIG. Rotation is restricted. When the guide flap 50 is in the first position, it is connected to the paper discharge tray 31 side (right side in FIG. 4). When the guide flap 50 is in the second position, the two-way path 39 is connected. In this way, the guide flap 50 guides the document to either the document transport path 32 or the two-way path 39 at the connection position 38. In FIG. 4, only one guide flap 50 is shown, but a plurality of guide flaps 50 of the same shape are provided at predetermined intervals in the width direction of the document conveying path 32, and the plurality of guide flaps 50 are provided. It is rotated integrally.

  As shown in FIG. 2, the document transport path 32 and the two-way path 39 are provided with a plurality of sensors for detecting document transport. Specifically, a first front sensor 52 is disposed in the document conveyance path 32 on the upstream side in the conveyance direction of the separation roller 34, and the second front sensor 53 (in the present invention) on the downstream side in the conveyance direction of the separation roller 34. An example of first detection means) is provided. A first sheet sensor 54 (an example of a second detection unit of the present invention) is disposed upstream of the reading position in the conveyance direction. Between the connection position 38 and the intersection position 40 of the two-way path 39, a second sheet sensor 55 (an example of the third detection means of the present invention) is disposed. Each of these sensors is a so-called optical sensor and has the same configuration except that the shape of the sensor actuator differs depending on the position to be detected. Therefore, in the present embodiment, the configuration of the first front sensor 52 will be described in detail by taking the first front sensor 52 as an example.

  FIG. 5 is an enlarged view showing the configuration of the first front sensor 52. As shown in the drawing, the first front sensor 52 protrudes from the lower surface of the document conveyance path 32 and rotates so as to retract from the document conveyance path 32 by contacting the document, and the sensor actuator 56. And a photo interrupter 57 for detecting the rotation. The sensor actuator 56 is integrally formed with a light shielding portion 58 that is detected by a photo interrupter 57, and is provided so as to be rotatable about a shaft 59. The sensor actuator 56 is elastically biased in a clockwise direction in FIG. 5 by a biasing means such as a spring (not shown) to a position where the sensor actuator 56 protrudes into the document conveyance path 32. In a state where no external force is applied to the sensor actuator 56, the sensor actuator 56 protrudes into the document conveyance path 32, and the light shielding portion 58 is located between the light emitting portion and the light receiving portion of the photo interrupter 57, as shown by a solid line in FIG. . Thereby, the light transmission of the photo interrupter 57 is interrupted, and the first front sensor 52 is turned off.

  When a document is placed on the paper feed tray 30, the document contacts the sensor actuator 56 and rotates the sensor actuator 56 in a direction to retract from the document transport path 32. The light shielding portion 58 is also rotated together with the sensor actuator 56, and the light shielding portion 58 is separated from between the light emitting portion and the light receiving portion of the photo interrupter 57, as shown by a two-dot chain line in FIG. Thereby, the light transmission of the photo interrupter 57 is not interrupted, and the first front sensor 52 is turned on. Whether the document is placed on the paper feed tray 30 is determined by turning on / off the first front sensor 52.

  The second front sensor 53 is disposed between the separation roller 34 and the intersection position 40. The second front sensor 53 detects the presence / absence of a document by turning it on / off. Based on the detection signal of whether the second front sensor 53 is on or off, the presence or absence of a document in the second front sensor 53 can be detected. The second front sensor 53 is also for detecting the transport position of the document, specifically, the transport positions of the leading edge and the trailing edge of the document. For example, the number of rotations of the transport rollers 35A, 35B, 35C, and 35D after the second front sensor 53 detects the leading edge or the trailing edge of the document depends on the number of steps of the motor 67 (see FIG. 6), the output value of the encoder, and the like. By monitoring, the position of the leading edge or trailing edge of the document in the document transport path is determined.

  The first sheet sensor 54 disposed upstream in the conveyance direction of the reading position is for detecting the leading edge and the trailing edge of the document conveyed on the document conveyance path 32 by turning on / off thereof. The number of rotations of the conveying rollers 35A, 35B, 35C, and 35D after the first sheet sensor 54 detects the leading edge or trailing edge of the document is counted by the number of steps of the motor 67 (see FIG. 6), the output value of the encoder, and the like. Thus, it is determined whether or not the leading edge or trailing edge of the document has reached the reading position. The image reading unit 22 is controlled based on the signal of the first sheet sensor 54. That is, the image reading unit 22 starts image reading when the leading edge of the document reaches the reading position, and ends image reading when the trailing edge of the document reaches the reading position.

  The document conveyance path 32 has a distance from the separation roller 34 to a predetermined switching position 45 (corresponding to a predetermined second position of the present invention, see FIG. 24) on the upstream side of the conveyance roller 35C in the conveyance direction. The length is set shorter than the minimum length of a document that can be conveyed by the ADF 3. More specifically, as will be described later, the distance from the leading end position of the document when the document is temporarily stopped on the upstream side of the transport roller 35C to the nip point between the separation roller 34 and the guide plate 19 is the minimum in the transportable document. It is set shorter than the length. Therefore, when the leading edge of the document reaches the vicinity of the upstream in the transport direction of the transport roller 35C, the rear end side of the document is nipped by the separation roller 34.

  The second sheet sensor 55 disposed between the connecting position 38 and the crossing position 40 of the two-way path 39 detects the leading edge or the trailing edge of the document conveyed on the two-way path 39 by turning on / off the second sheet sensor 55. Is for. For example, the number of rotations of the transport rollers 35A, 35B, 35C, and 35D and the reversible roller 43 after the second sheet sensor 55 detects the trailing edge of the document is the number of steps of the motor 67 (see FIG. 6) or the output value of the encoder. For example, it is determined whether or not the trailing edge of the document has passed the intersection position 40.

  FIG. 6 shows a configuration of the control unit 60 of the image reading apparatus 1. The control unit 60 controls the overall operation of the image reading apparatus 1 in an integrated manner. As shown in the figure, the control unit 60 is a microcomputer including a CPU (Central Processing Unit) 61, a ROM (Read Only Memory) 62, a RAM (Random Access Memory) 63, and an EEPROM (Electrically Erasable and Programmable ROM) 64. And is connected to an ASIC (Application Specific Integrated Circuit) 66 via a bus 65.

  The ROM 62 stores a program for controlling various operations of the image reading apparatus 1 and the ADF 3. The RAM 63 is used as a storage area or work area for temporarily storing various data used when the CPU 61 executes the program, and a storage area for correction information, conveyance mode information, reading state information, and rotation direction information, which will be described later. Is done. The ROM 62 and the RAM 62 are supplied with power from a backup power source, and can retain information stored in the RAM 63 even when the apparatus is turned off. The EEPROM 64 is a storage area for storing various settings, flags, and the like that should be stored even after the power is turned off. The CPU 61, ROM 62, RAM 63, and EEPROM 64 implement the control means of the present invention.

  The ASIC 66 generates a phase excitation signal or the like for energizing the motor 67 in accordance with a command from the CPU 61, applies the signal to the drive circuit 68 of the motor 67, and energizes the motor 67 via the drive circuit 68. Thus, rotation control is performed. The motor 67 is rotationally driven in either the forward rotation direction or the reverse rotation direction (forward / reverse bidirectional), thereby causing the pickup roller 33, the separation roller 34, the transport rollers 35A, 35B, 35C, 35D, and the paper discharge roller. 36, a driving force is applied to the reversible roller 43 and the guide flap 50. The motor 67 is a single drive source in the ADF 3. The motor 67 can be applied to any configuration and any drive system as long as it can be driven to rotate in both directions of forward rotation (CW rotation) or reverse rotation (CCW rotation). In this embodiment, a stepping motor that is driven and controlled by a pulse driving method will be described. The history of the stop command to the motor 67 and the forward rotation (CW rotation) command or the reverse rotation (CCW rotation) command is stored in the RAM 63.

  The drive circuit 68 receives the output signal from the ASIC 66 and generates a pulse signal for rotating the motor 67. This pulse signal is generated based on the periodic signal generated by the ASIC 66. The pulse signal generated by the drive circuit 68 is output to the motor 67. When the pulse signal is input, the motor 67 rotates in a predetermined rotational direction, and the rotational force of the motor 67 is picked up by the pickup roller 33 and the separation roller 34 via the respective gear systems 70, 110, 120, 150, 170 described later. The transfer rollers 35 </ b> A, 35 </ b> B, 35 </ b> C, 35 </ b> D, the paper discharge roller 36, the reversible roller 43, and the guide flap 50 are transmitted.

  The periodic signal generated by the ASIC 66 is fed back to the CPU 61 via the bus 65. Based on the fed back periodic signal, the CPU 61 counts the number of pulses of the pulse signal generated by the drive circuit 68. Note that the counted pulse signal is temporarily stored in the RAM 63 as the number of steps of the motor 67.

  The image reading unit 22 is connected to the ASIC 66. The image reading unit 22 reads an image of a document based on a control program stored in the ROM 62. Although not shown in FIG. 6, the drive mechanism for reciprocating the image reading unit 22 is also operated in response to an output signal from the ASIC 66.

  A first front sensor 52, a second front sensor 53, a first sheet sensor 54, and a second sheet sensor 55 are connected to the ASIC 66. The CPU 61 receives ON / OFF of each sensor and causes the ASIC 66 to output a predetermined output signal based on a control program stored in the ROM 62. The on / off history of each sensor is stored in the RAM 63. Of the ON / OFF history of each sensor, the ON / OFF history of the first sheet sensor 54 and the second sheet sensor 55 is used as the reading state information.

  A solenoid 88 and a solenoid 161 are connected to the ASIC 66. Based on the control program stored in the ROM 62, the CPU 61 causes the ASIC 66 to output an output signal at a predetermined timing to operate the solenoid 88 and the solenoid 161.

  Hereinafter, a driving force transmission mechanism from the motor 67 to the pickup roller 33, the separation roller 34, the transport rollers 35A, 35B, 35C, and 35D, the paper discharge roller 36, the reversible roller 43, and the guide flap 50 will be described. The shafts of the separation roller 34, the transport rollers 35 </ b> A, 35 </ b> B, 35 </ b> C, 35 </ b> D, the paper discharge roller 36, the reversible roller 43, and the guide flap 50 are extended in the width direction of the document transport path 32. The separation roller 34, the transport rollers 35 </ b> A, 35 </ b> B, 35 </ b> C, 35 </ b> D, the paper discharge roller 36, the reversible roller 43, and the guide flap 50 are provided at predetermined positions on the respective axes according to the width of the document transport path 32. Of course, each roller or the like may be provided over substantially the entire axial direction of each axis, or a plurality of rollers or the like may be coaxially arranged at predetermined intervals in the width direction of the document conveyance path 32.

  As shown in FIG. 1, the ADF 3 provided on the upper surface of the document cover 4 has a document conveyance path 32 and each roller accommodated in a housing. A motor 67 for applying a driving force to each roller and a driving force transmission mechanism are also accommodated in the casing of the ADF 3. A driven gear is provided at one end of each shaft of the separation roller 34, the transport rollers 35 </ b> A, 35 </ b> B, 35 </ b> C, 35 </ b> D, the paper discharge roller 36, the reversible roller 43, and the guide flap 50. Each roller is driven by transmitting a driving force from the motor 67 to each driven gear via each driving force transmission mechanism. In the present embodiment, each axis of the motor 67, each driving force transmission mechanism, the solenoid 88, the solenoid 161, the separation roller 34, the transport rollers 35A, 35B, 35C, and 35D, the paper discharge roller 36, the reversible roller 43, and the guide flap 50. A driven gear is provided on one end side. Each driven gear is accommodated in a gear box 7 provided on the rear side of the housing of the ADF 3. Each gear shown below is a spur gear in which teeth parallel to the axis are formed on the outer periphery unless otherwise limited.

  7 to 11 show the first gear system 70 from the motor 67 to the separation roller 34. In the first gear system 70 (an example of the second transmission mechanism of the present invention), when the motor 67 rotates clockwise (CW: clock wise), the separation roller 34 is rotated in the feeding direction, and the CW rotation is counterclockwise. The transmission of the driving force to the separation roller 34 is cut off by switching to rotation (CCW: counter clock wise). CW rotation and CCW rotation are opposite rotation directions of the motor 67, and correspond to forward rotation and reverse rotation, respectively. The first gear system 70 and the second gear system 120, the third gear system 150, and the fifth gear system 151 described later implement the transmission means of the present invention.

  As shown in FIG. 7, four transmission gears 71, 72, 73, 74 are sequentially meshed with a driving gear 69 provided on the driving shaft of the motor 67, and the driving force is transmitted to the planetary gear device 75. ing. The four transmission gears 71, 72, 73, 74 are not particularly limited, and are appropriately provided according to the distance from the drive gear 69 to the planetary gear device 75. The number and diameter of the transmission gear can be changed. In response to the CW rotation or CCW rotation of the motor 67, the sequentially engaged transmission gears 71, 72, 73 rotate in a predetermined direction, and the driving force is transmitted so that the transmission gear 74 rotates CCW or CW.

  FIG. 9 shows the configuration of the planetary gear device 75. In the planetary gear device 75, a support arm 78 is rotatably provided coaxially with the shaft 77 of the sun gear 76, and two planetary gears 79 and 80 that respectively mesh with the sun gear 76 are supported on the support arm 78. Become. In the present embodiment, the planetary gear device 75 has the two planetary gears 79 and 80. However, the number of planetary gears is not particularly limited. For example, the planetary gear unit 75 has only one planetary gear. It doesn't matter.

  The sun gear 76 is a two-stage gear in which a large-diameter gear 76L and a small-diameter gear 76S are coaxially and integrally configured. The support arm 78 has arm portions 81 and 82 extending in two radial directions from the shaft 77, and the planetary gears 79 and 80 are respectively pivoted by bearing portions 83 and 84 formed at the tips of the arm portions 81 and 82. It is something to support. The planetary gears 79 and 80 pivotally supported by the support arm 78 mesh with the gear 76S of the sun gear 76, respectively. When the sun gear 76 rotates, the planetary gears 79 and 80 respectively meshed with the gear 76S rotate. The support arm 78 also rotates in the same direction in response to the rotation of the sun gear 76. That is, when the sun gear 76 rotates, the planetary gears 79 and 80 revolve around the sun gear 76 while rotating.

  A locking recess 85 is formed in the vicinity of the shaft 77 of the support arm 78. The first gear system 70 includes a locking mechanism 86. When the locking recess 85 is locked to the locking mechanism 86, the support arm 78 is stopped at a predetermined position regardless of the rotation of the sun gear 76. A position where the support arm 78 is locked to the locking mechanism 86 is a detachment position described later.

  The locking mechanism 86 includes a locking member 87 and a solenoid 88. The locking member 87 includes an arm part 90, a claw 91, and a passive part 92. The arm portion 90 extends in the radial direction from the shaft 89 toward the support arm 78. The claw 91 is formed in a hook shape at the tip of the arm portion 90. The passive portion 92 extends from the shaft 89 in the radial direction. The claw 91 can be engaged with the recess 85 of the support arm 78. The claw 91 is detached from the recess 85 by rotating the arm portion 90 about the shaft 89. The passive portion 92 is connected to the shaft 93 of the solenoid 88. When the power is turned on, an electromagnetic force is applied to the solenoid 88 so that the shaft 93 is immersed in the main body, and when the power is turned off, the electromagnetic force disappears and the shaft 93 is protruded from the main body. It's something that makes you The drive of the shaft 93 is transmitted to the passive portion 92, and the locking member 87 is rotated about the shaft 89 to assume a predetermined posture. With the solenoid 88 turned off, the claw 91 engages with the recess 85 of the support arm 78 as shown by the solid line in FIG. . When the solenoid 88 is on, the claw 91 is detached from the recess 85 as shown by a two-dot chain line in FIG.

  As shown in FIG. 7, the transmission gear 74 meshes with the gear 76 </ b> L of the sun gear 76 of the planetary gear device 75. A driving force is transmitted from the motor 67 to the transmission gear 74, and the sun gear 76 is rotated in a predetermined direction. For example, as shown in FIG. 7, when the drive gear 69 rotates CW, the transmission gear 74 rotates CW and the sun gear 76 rotates CCW. Since the support arm 78 is rotatable when the solenoid 88 is on, the planetary gears 79 and 80 revolve by CCW rotation. The solenoid 88 only needs to be turned on when the claw 91 is detached from the locking recess 85. Even if the solenoid 88 is turned off after the support arm 78 is rotated from the disengaged position, the claw 91 is not locked. 85 is not engaged.

  As shown in FIG. 8, a transmission gear 94 is disposed adjacent to the planetary gear device 75. The transmission gear 94 can be separated from the planetary gears 79 and 80 of the planetary gear device 75. As shown in FIG. 8, the planetary gears 79 and 80 revolve around the CCW rotation, so that the planetary gear 79 meshes with the transmission gear 94 and the planetary gear 80 moves away from the transmission gear 94. The transmission gear 94 is a two-stage gear in which a large-diameter gear 94L and a small-diameter gear 94S are coaxially and integrally configured. The planetary gears 79 and 80 can be engaged with and disengaged from the large-diameter gear 94L. The small-diameter gear 94S meshes with a driven gear 95 provided on a shaft 111 (see FIG. 12) that supports the separation roller 34. The gear configuration from the transmission gear 94 to the driven gear 95 is not particularly limited, and the number and diameter of the transmission gears can be appropriately changed according to the distance from the transmission gear 94 to the driven gear 95.

  When the planetary gear 79 revolved by the CCW rotation meshes with the transmission gear 94, the revolution of the planetary gear 79 is stopped. Then, the planetary gear 79 receives the driving force from the sun gear 76 and rotates by CW rotation. In response to this, the transmission gear 94 rotates CCW, and the driven gear 95 rotates CW. As the driven gear 95 rotates CW, the shaft 111 that supports the separation roller 34 is rotated in the transport direction.

  As shown in FIG. 10, when the drive gear 69 is switched from CW rotation to CCW rotation, the transmission gear 74 rotates CCW and the sun gear 76 rotates CW. As shown in FIG. 8, when the planetary gear 79 is engaged with the transmission gear 94, the claw 91 does not engage with the locking recess 85 even if the solenoid 88 is off. Therefore, since the support arm 78 is rotatable, the planetary gears 79 and 80 revolve by CW rotation. As the planetary gears 79 and 80 revolve, the support arm 78 rotates, so that the locking recess 85 of the support arm 85 can be engaged with the claw 91. At this time, if the solenoid 88 is off, the claw 91 engages with the locking recess 85 and the rotation of the support arm 78 is restricted as shown in FIG. In this state, both the planetary gears 79 and 80 are not meshed with the transmission gear 94. The position of the support arm 78 at which the planetary gears 79 and 80 are separated from the transmission gear 94 is referred to as a detached position in this specification. When the claw 91 is engaged with the locking recess 85, the support arm 78 is locked so as not to rotate, and the support arm 78 is held in the disengaged position until the solenoid 88 is turned on.

  As shown in FIG. 11, when the solenoid 88 is turned on, the planetary gears 79 and 80 revolve with the CW rotation based on the CW rotation of the sun gear 76. When the planetary gear 80 revolved by the CW rotation is engaged with the transmission gear 94, the revolution of the planetary gear 80 is stopped. Then, the planetary gear 80 rotates by CCW rotation upon receiving the driving force transmitted from the sun gear 76. In response to this, the transmission gear 94 rotates CW, and the driven gear 95 rotates CCW. As the driven gear 95 rotates CCW, the shaft 111 that supports the separation roller 34 is rotated in the direction opposite to the conveying direction.

  Hereinafter, the second gear system 110 from the shaft 111 that supports the separation roller 34 to the pickup roller 33 will be described. As shown in FIG. 2, the pickup roller 33 is pivotally supported on the distal end side of the arm 29 and is arranged on the opposite side of the separation roller 34. As described above, the driving force of the motor 67 is transmitted to the shaft 111, and the driving force is transmitted from the shaft 111 to the arm 29, the pickup roller 33, and the separation roller 34.

  FIG. 12 shows the second gear system 110 from the shaft 111 to the pickup roller 33. The second gear system 110 includes a one-round clutch 112 provided on the shaft 111, a gear 113 formed integrally with the separation roller 34, a gear 115 fixed to the shaft 114 of the pickup roller 33, and a gear from the gear 113. And a transmission gear 116 for transmitting a driving force to 115. The separation roller 34 is rotatably supported on the shaft 111. The one-round clutch 112 and the gear 113 are respectively provided on both sides in the axial direction of the separation roller 34. In FIG. 12, the one-round clutch 112 is provided on the rear side of the separation roller 34 in FIG. Since the gear 113 is provided on the front side of the sheet of FIG. 12, the one-round clutch 112 on the back side of the separation roller 34 is indicated by a broken line.

  The one-round clutch 112 includes a pin 117 projecting from the shaft 111 and a projecting piece 118 projecting laterally from the separation roller 34. The pin 117 protrudes in the radial direction of the shaft 111 on the side of the separation roller 34, and rotates with the rotation of the shaft 111. The protruding piece 118 protrudes in the axial direction from the side surface of the separation roller 34. The position of the protruding piece 118 with respect to the radial direction of the separation roller 34 is within the range of the protruding length of the pin 117, and the pin 117 and the protruding piece 118 can be engaged with each other. As shown in FIG. 12, when the pin 117 is engaged with the projecting piece 118, the rotation of the shaft 111 is transmitted to the separation roller 34 via the pin 117 and the projecting piece 118, and the separation roller 34 is integrated with the shaft 111. Rotate to.

  Since the separation roller 34 is movable in the direction of the shaft 111, the separation roller 34 is movable in a direction in which the protruding piece 118 is separated from the pin 117. Then, when the separation roller 34 rotates about one turn with respect to the shaft 111, the projecting piece 118 comes into contact with the pin 117 again. As a result, the separation roller 34 can rotate idly for approximately one round regardless of the transmission of the driving force from the shaft 111.

  A transmission gear 116 is interposed between the gear 113 provided on the separation roller 34 and the gear 115 fixed to the shaft 114 of the pickup roller 33. The transmission gear 116 meshes with the gear 113 and the gear 115. Since the gear 113 is integral with the separation roller 34, the gear 113 is rotated as the separation roller 34 rotates. The transmission gear 116 is rotated by the rotation of the gear 113, and the gear 115 is rotated by the rotation of the transmission gear 116. Since the gear 115 is fixed to the shaft 114 of the pickup roller 33, a rotational force is transmitted to the pickup roller 33 as the gear 115 rotates. That is, the separation roller 34 and the pickup roller 33 are always rotated in the same direction. By such a second gear system 110, a driving force is transmitted from the shaft 111 that rotatably supports the separation roller 34 to the separation roller 34 and the pickup roller 33.

  As shown in FIG. 12, the base end side of the arm 29 is rotatably supported by a shaft 111, and moves up and down when a driving force is transmitted from the shaft 111. A cylindrical body (not shown) is attached to the shaft 111, and a slip clutch is provided between the cylindrical body and the arm base end. The rotation of the shaft 111 is transmitted to the arm 29 by the cylindrical body and the sliding clutch. The slip clutch is slid between the cylindrical body and the arm base end by receiving a load equal to or higher than a predetermined torque, and the driving force transmission is cut off. As the shaft 111 rotates CW, the rotational force in the same direction is transmitted to the arm 29 via the cylinder and the slip clutch, and the arm 29 is lowered. On the other hand, if the shaft 111 rotates CCW, the arm 29 rises. As shown in FIG. 2, when the arm 29 is lowered, the pickup roller 33 comes into contact with the guide surface of the document transport path 32 or the document on the paper feed tray 30. In this state, when the shaft 111 further rotates, the clutch slides with respect to the cylindrical body and stops in a state where the arm 29 is lowered. As described above, the driving force is transmitted from the shaft 111 to the arm 29 via the cylinder and the slip clutch, and the arm 29 swings so that the pickup roller 33 is lowered or raised with respect to the guide surface of the document conveying path 32. Is done. The mechanism for moving the arm 29 up and down depending on whether or not the driving force is transmitted is not necessarily required in the present invention, and may be omitted.

  13 to 15 show a third gear system 120 (an example of the first transmission mechanism of the present invention) from the motor 67 to the transport rollers 35A, 35B, 35C, and 35D. The third gear system 120 is a drive that conveys a document from the conveyance roller 35A, 35B, 35C, 35D to the conveyance direction, that is, from the upstream side in the conveyance direction of the document conveyance path 32 to the downstream side in the conveyance direction regardless of the rotation direction of the motor 67. It conveys power.

  As shown in FIG. 13, a transmission gear 121 is meshed with a drive gear 69 provided on the drive shaft of the motor 67, and the driving force is transmitted to the planetary gear device 122. The number of gears from the drive gear 69 to the transmission gear 121 is not particularly limited, and the number and diameter of the transmission gears can be changed according to the distance from the drive gear 69 to the planetary gear device 122. The transmission gear 121 receives the CW rotation or CCW rotation of the motor 67 and transmits the driving force so as to rotate CCW or CW.

  In the planetary gear device 122, a support arm 125 is rotatably provided coaxially with the shaft 124 of the sun gear 123. One planetary gear 126 that meshes with the sun gear 123 is pivotally supported on the support arm 125. In the present embodiment, the planetary gear device 122 has one planetary gear 126, but the number of planetary gears is not particularly limited. For example, as in the planetary gear device 75 described above, It may have two planetary gears.

  The sun gear 123 is a two-stage gear in which a large-diameter gear 123L and a small-diameter gear 123S are coaxially and integrally configured. The planetary gear 126 pivotally supported by the support arm 125 meshes with the gear 123S of the sun gear 123. When the sun gear 123 rotates, the planetary gear 126 meshed with the gear 123S rotates. In addition, since the pickup roller 33 is attached to the shaft via a torque limiter, the support arm 125 also rotates in the same direction in response to the rotation of the sun gear 123. That is, when the sun gear 123 rotates, the planetary gear 126 revolves around the sun gear 123 while rotating.

  The transmission gear 121 meshes with the gear 123 </ b> L of the sun gear 123 of the planetary gear device 122. When the driving force is transmitted from the motor 67 and the transmission gear 121 rotates in a predetermined direction, the sun gear 123 rotates in the predetermined direction. For example, as shown in FIG. 13, when the drive gear 69 rotates CCW, the transmission gear 121 rotates CW, the sun gear 123 rotates CCW, and the planetary gear 126 revolves with respect to the sun gear 123 by CCW rotation.

  As shown in FIG. 13, a transmission gear 128 and a transmission gear 129 are arranged adjacent to the planetary gear device 122. The transmission gear 128 is a two-stage gear in which a large-diameter gear 128L and a small-diameter gear 128S are coaxially and integrally configured. Similarly, the transmission gear 129 is a two-stage gear in which a large-diameter gear 129L and a small-diameter gear 129S are coaxially and integrally configured. The planetary gear 126 of the planetary gear device 122 can be engaged with and disengaged from the gear 128L of the transmission gear 128. The planetary gear 126 also meshes with the gear 129L of the transmission gear 129. Furthermore, the gear 128L and the gear 129L are meshed.

  As shown in FIG. 13, the planetary gear 126 revolves by CCW rotation while meshing with the sun gear 123. Thereby, the planetary gear 126 meshes with the gear 128L of the transmission gear 128. At this time, the planetary gear 126 is disengaged from the transmission gear 129. When the planetary gear 126 revolved by the CCW rotation meshes with the transmission gear 128, the revolution of the planetary gear 126 is stopped. And the planetary gear 126 rotates by CW rotation in response to transmission of driving force from the sun gear 123. In response to this, the transmission gear 128 rotates CCW. The transmission gear 129 that meshes with the transmission gear 128 rotates CW.

  As shown in FIG. 14, when the drive gear 69 rotates CW, the transmission gear 121 rotates CCW and the sun gear 123 rotates CW. At this time, the planetary gear 126 revolves by CW rotation. Then, the planetary gear 126 revolves by CW rotation, so that the planetary gear 126 meshes with the gear 129L of the transmission gear 129. At this time, the planetary gear 126 is disengaged from the transmission gear 128 and thus is not engaged. When the planetary gear 126 revolved by the CW rotation is engaged with the transmission gear 129, the revolution of the planetary gear 126 is stopped. Then, the planetary gear 126 receives the driving force from the sun gear 123 and rotates by CCW rotation. In response to this, the transmission gear 129 rotates CW. The transmission gear 128 that meshes with the transmission gear 129 rotates CCW. In this way, regardless of whether the drive gear 69 is CW rotation or CCW rotation, the driving force for CCW rotation is transmitted to the transmission gear 128, and the driving force for CW rotation is transmitted to the transmission gear 129. . In other words, regardless of the rotation direction of the motor 67 connected to the drive gear 69, the drive force for rotating each gear in a fixed rotation direction is transmitted to the transmission gear 128 and the transmission gear 129.

  FIG. 15 shows transmission of driving force from the transmission gears 128 and 129 to the respective transport rollers 35A, 35B, 35C, and 35D and the paper discharge roller 36. The gear 128S of the transmission gear 128 is sequentially meshed with the five transmission gears 130, 131, 132, 133, and 134. The transmission gear 133 meshes with a driven gear 135 provided on the shaft of the transport roller 35A. The transmission gear 134 meshes with a driven gear 136 provided on the shaft of the paper discharge roller 36. The driving force of the transmission gear 128 is transmitted to the transport roller 35A via the transmission gears 130, 131, 132, 133 and the driven gear 135. Further, the driving force of the transmission gear 128 is transmitted to the paper discharge roller 36 via the transmission gears 130, 131, 132, 133, 134 and the driven gear 136.

  As described above, the transmission gear 128 is CCW rotated regardless of the rotation direction of the drive gear 69, and the driving force is sequentially transmitted from the transmission gear 128 to the five transmission gears 130, 131, 132, 133, and 134. In response, the driven gear 135 rotates CW, and the driven gear 136 rotates CCW. As the driven gear 125 rotates CW, the transport roller 35A rotates in the transport direction. Further, as the driven gear 126 rotates in the CCW direction, the paper discharge roller 36 rotates in the direction in which the original is discharged to the paper discharge tray 31.

  Three transmission gears 137, 138, and 139 are sequentially meshed with the gear 129S of the transmission gear 129. Then, the driven gear 140 provided on the shaft of the conveying roller 35D is engaged with the gear 129S, the driven gear 141 provided on the shaft of the conveying roller 35C is engaged with the transmission gear 138, and the conveying roller 139 is engaged with the conveying roller 139. A driven gear 142 provided on the shaft of 35B is meshed. Thereby, the driving force of the transmission gear 129 is transmitted to the transport roller 35D via the driven gear 140. Further, the driving force of the transmission gear 129 is transmitted to the transport roller 35C via the transmission gear 138 and the driven gear 141. Further, the driving force of the transmission gear 129 is transmitted to the transport roller 35B via the transmission gear 139 and the driven gear 142.

  As described above, the transmission gear 129 is CW rotated regardless of the rotation direction of the drive gear 69, and the driving force is sequentially transmitted from the transmission gear 129 to the three transmission gears 137, 138, and 139. In response to this, the driven gears 140 and 141 rotate CCW and the driven gear 142 rotates CW. As the driven gears 140 and 141 rotate CCW, the transport rollers 35D and 35C are rotated in the transport direction. As the driven gear 142 rotates CW, the transport roller 35B is rotated in the transport direction. In this manner, the driving force in the transport direction is transmitted to the transport rollers 35A, 35B, 35C, and 35D and the paper discharge roller 36 in the rotational direction of the drive gear 69. Note that the gear configuration from the transmission gears 128 and 129 to the driven gears 135, 136, 140, 141, and 142 is not particularly limited, and the transmission gears are arranged according to the distances from the transmission gears to the driven gears. The number and diameter can be changed as appropriate.

  16 to 18 show the fourth gear system 150 and the fifth gear system 151 from the motor 67 to the reversible roller 43. The fourth gear system 150 transmits the driving force in the retracting direction or the returning direction to the reversible roller 43 based on the rotation direction of the motor 67. Specifically, the fourth gear system 150 transmits to the reversible roller 43 a driving force in a direction to return the document in the two-way path 39 from the opening side to the document transport path 32 when the motor 67 rotates CW. When the 67 rotates CCW, the driving force for conveying the document to the opening side is transmitted to the reversible roller 43. The fourth driving system 150 and the motor 67 implement the first driving force supply means of the present invention.

  The fifth gear system 151 cuts off the driving force transmission from the motor 67 to the reversible roller 43 when the rotation direction of the motor 67 is switched from the return direction of the reversible roller 43 to the retracting direction. Here, the drawing direction is a direction in which the document is drawn from the intersection position 40 of the upper portion 32A of the document conveyance path 32 to the end 41 side of the two-way path 39, and the return direction is the end 41 side of the two-way path 39. This is the direction in which the original is returned from the original to the original conveyance path 32. In the present embodiment, the mechanism constituted by the fourth gear system 150 and the motor 67 is exemplified as the first driving force supply means. However, for example, a driving source such as a motor different from the motor 67 is provided. The driving force may be supplied to the reversible roller 43 by controlling the rotation of the driving source. With such a mechanism, the transmission mechanism from the drive source to the reversible roller 43 can be simplified.

  As shown in FIG. 16, the transmission gear 152 is meshed with a driving gear 69 provided on the driving shaft of the motor 67, and the driving force is transmitted to the planetary gear device 153. The configuration from the drive gear 69 to the transmission gear 152 is not particularly limited, and the number and diameter of the transmission gears can be changed according to the distance from the drive gear 69 to the planetary gear device 153. In response to the CW rotation or CCW rotation of the motor 67, the driving force is transmitted so that the transmission gear 152 rotates CCW or CW.

  In the planetary gear device 153, a support arm 156 is rotatably provided coaxially with the shaft 155 of the sun gear 154, and two planetary gears 157 and 158 that mesh with the sun gear 154 are supported on the support arm 156, respectively. Become. In the present embodiment, the planetary gear device 153 has the two planetary gears 157 and 158. However, the number of planetary gears is not particularly limited. For example, the planetary gear device 122 is the same as the planetary gear device 122 described above. Alternatively, it may have only one planetary gear.

  The sun gear 154 is a two-stage gear in which a large-diameter gear 154L and a small-diameter gear 154S are coaxially and integrally configured. The support arm 156 is rotatably provided on the shaft 155 and supports the planetary gears 157 and 158, respectively. The planetary gears 157 and 158 pivotally supported by the support arm 156 mesh with the gear 154S of the sun gear 154, respectively. When the sun gear 154 rotates, the planetary gears 157 and 158 respectively engaged with the gear 154S rotate. Further, the support arm 156 also rotates in the same direction in response to the rotation of the sun gear 154. That is, when the sun gear 154 rotates, the planetary gears 157 and 158 revolve around the sun gear 154 while rotating.

  A convex portion 159 is formed in the vicinity of the tip where the support arm 156 pivotally supports the planetary gear 157. When the convex portion 159 is locked to the fifth gear system 151, the support arm 156 that rotates CCW with respect to the shaft 155 of the sun gear 154 is stopped at a predetermined position. As shown in FIG. 16, the position where the support arm 156 is locked to the fifth gear system 151 is a disengagement position described later.

  The fifth gear system 151 includes a locking member 160 and a solenoid 161. The locking member 160 includes an arm portion 163 that extends in a radial direction from the shaft 162 toward the support arm 156, a claw 164 that is formed in a hook shape at the tip of the arm portion 163, and a radial direction that extends from the shaft 162. And a passive part 165 that has been brought out. The claw 164 can be engaged with the convex portion 159 of the support arm 156, and the arm portion 163 is engaged with and disengaged from the convex portion 159 when the arm portion 163 is rotated about the shaft 162. The passive portion 165 is connected to the shaft 166 of the solenoid 161. The solenoid 161 is actuated by electromagnetic force when electric power is supplied (turned on), and linearly drives the shaft 166 in a direction to be immersed in the main body. When the electric power is cut off (off), the electromagnetic force disappears. Then, the shaft 166 is elastically returned linearly in the direction in which the shaft 166 protrudes from the main body. The driving of the shaft 166 is transmitted to the passive portion 165, and the locking member 160 is rotated about the shaft 162 to assume a predetermined posture.

  With the solenoid 161 turned off, as shown by the solid line in FIG. 16, the locking member 160 is in a posture in which the claw 164 can engage with the convex portion 159 of the support arm 156. The locking member 160 can rotate clockwise from this engagement posture, and is biased by a spring or the like to maintain the engagement posture unless receiving external force. The convex portion 159 rotates with the rotation of the support arm 156, and the rotation direction thereof is the substantially radial direction of the locking member 160 in the engagement posture. Therefore, even if the rotational force of the support arm 156 is transmitted to the locking member 160 via the convex portion 159, the locking member 160 does not rotate from the engagement posture against the urging force of a spring or the like. With the solenoid 161 turned on, the locking member 160 is in a posture to release the claw 164 from the convex portion 159 as shown by a two-dot chain line in FIG.

  As shown in FIG. 16, the transmission gear 152 meshes with the gear 156 </ b> L of the sun gear 154 of the planetary gear device 153. When the driving force is transmitted from the motor 67 and the transmission gear 152 rotates in a predetermined direction, the sun gear 154 is rotated in a predetermined direction. For example, as shown in FIG. 16, when the drive gear 69 rotates CCW, the transmission gear 152 rotates CW and the sun gear 154 rotates CCW. In response to this, the planetary gears 157 and 158 revolve by CCW rotation. As the planetary gears 157 and 158 revolve, the support arm 156 rotates, so that the convex portion 159 of the support arm 156 can be engaged with the claw 164. At this time, if the solenoid 161 is off, the claw 164 engages with the projection 159 as shown in FIG. 16, and the rotation of the support arm 156 is restricted. In this state, both the planetary gears 157 and 158 are not meshed with the transmission gear 167. The position of the support arm 156 from which the planetary gears 157 and 158 are separated from the transmission gear 167 is referred to as a detached position in this specification. When the claw 164 is engaged with the convex portion 159, the CCW rotation of the support arm 156 is restricted until the solenoid 161 is turned on, and the support arm 156 is held in the disengaged position.

  As shown in FIG. 16, the transmission gear 167 is disposed at a position adjacent to the planetary gear device 153. The transmission gear 167 can be separated from the planetary gears 157 and 158 of the planetary gear device 153. The transmission gear 167 is a two-stage gear in which a large-diameter gear 167L and a small-diameter gear 167S are coaxially and integrally configured. The planetary gears 157 and 158 can be separated from the large-diameter gear 167L. The small-diameter gear 167S meshes with a driven gear 168 provided on the shaft of the reversible roller 43. The gear configuration from the transmission gear 167 to the driven gear 168 is not particularly limited, and the number and diameter of the transmission gears can be appropriately changed according to the distance from the transmission gear 167 to the driven gear 168.

  As shown in FIG. 17, when the drive gear 69 rotates CW, the transmission gear 152 rotates CCW and the sun gear 154 rotates CW. In response to this, the planetary gears 157 and 158 revolve by CW rotation. As the planetary gears 157 and 158 revolve, the support arm 156 rotates. When the support arm 156 rotates CW, the convex portion 159 moves away from the claw 164. Therefore, even if the solenoid 161 is off, the support arm 159 can perform CW rotation. As the planetary gears 157 and 158 revolve by CW rotation, the planetary gear 157 meshes with the transmission gear 167.

  When the planetary gear 157 revolved by the CW rotation is engaged with the transmission gear 167, the revolution of the planetary gear 157 is stopped. And the planetary gear 157 rotates by CCW rotation in response to transmission of driving force from the sun gear 154. In response to this, the transmission gear 167 rotates CW and the driven gear 168 rotates CCW. As the driven gear 168 rotates CCW, the reversible roller 43 is rotated in the return direction.

  When the solenoid 161 is turned on from the state shown in FIG. 16, the shaft 166 is immersed in the main body. Thereby, the locking member 160 is rotated and the claw 164 is detached from the convex portion 159. Accordingly, the support arm 156 can rotate in the CCW direction, and the planetary gears 157 and 158 revolve in the CCW rotation. As shown in FIG. 18, the planetary gear 158 revolved by CCW rotation meshes with the transmission gear 167, whereby the revolution of the planetary gear 158 is stopped. Then, the planetary gear 158 rotates by CW rotation upon receiving the driving force from the sun gear 154. In response, the transmission gear 167 rotates CCW and the driven gear 168 rotates CW. As the driven gear 168 rotates in the CW direction, the reversible roller 43 is rotated in the retracting direction. The solenoid 161 may be turned on only when the claw 164 is detached from the convex portion 159. Even if the solenoid 161 is turned off after the support arm 156 is CCW rotated from the disengaged position, the claw 164 is protruded from the convex portion 159. Does not engage.

  When the rotation of the drive gear 67 is switched from CCW rotation to CW rotation, the support arm 156 can perform CW rotation from the state shown in FIG. 18 where the planetary gear 158 and the transmission gear 167 are engaged. When the support arm 156 rotates CW, the planetary gear 157 and the transmission gear 167 are engaged with each other as shown in FIG. Then, when the rotation of the drive gear 67 is switched from CW rotation to CCW rotation, the support arm 156 rotates CCW from the state shown in FIG. 17, and the claw 164 and the convex portion 159 are engaged as shown in FIG. It becomes the leaving position to do.

  19 and 20 show a sixth gear system 170 from the motor 67 to the guide flap 50. The sixth gear system 170 and the motor 67 implement the second driving force supply means of the present invention. The sixth gear system 170 transmits the rotational driving force based on the rotation direction of the motor 67 to the guide flap 50, and changes the guide flap 50 to the first position or the second position. In the present embodiment, the mechanism constituted by the sixth gear system 170 and the motor 67 is exemplified as the second driving force supply means. However, for example, a driving source such as a motor different from the motor 67 is provided. The driving force of this driving source may be supplied to the guide flap 50.

  As shown in FIG. 19, transmission gears 171, 172, and 173 are sequentially meshed with a driving gear 69 provided on the driving shaft of the motor 67, and the driving force is transmitted from the transmission gear 173 to the planetary gear device 174. ing. The number of gears from the drive gear 69 to the transmission gear 173 is not particularly limited, and the number and diameter of the transmission gears can be changed according to the distance from the drive gear 69 to the planetary gear device 174. Upon receiving the CW rotation or CCW rotation of the motor 67, the driving force is transmitted so that the transmission gear 173 rotates CCW or CW.

  The planetary gear device 174 is provided with a support arm 177 that is rotatable coaxially with the shaft 176 of the sun gear 175, and two planetary gears 178 and 179 that respectively mesh with the sun gear 175 are supported by the support arm 177. Become. In the present embodiment, the planetary gear device 174 has the two planetary gears 178 and 179. However, the number of planetary gears is not particularly limited. For example, the planetary gear device 122 is the same as the planetary gear device 122 described above. Alternatively, it may have only one planetary gear.

  The sun gear 175 is a two-stage gear in which a large-diameter gear 175L and a small-diameter gear 175S are coaxially and integrally configured. The planetary gears 178 and 179 that are pivotally supported by the support arm 177 mesh with the gear 175S of the sun gear 175, respectively. When the sun gear 175 rotates, the planetary gears 178 and 179 respectively engaged with the gear 175S rotate. Further, the support arm 177 rotates in the same direction in response to the rotation of the sun gear 175. That is, when the sun gear 175 rotates, the planetary gears 178 and 179 revolve around the sun gear 175 while rotating respectively.

  The transmission gear 173 meshes with the sun gear 175 of the planetary gear device 174. When the driving force is transmitted from the motor 67 and the transmission gear 173 rotates in a predetermined direction, the sun gear 175 is rotated in the predetermined direction. For example, as shown in FIG. 19, when the drive gear 69 rotates CW, the transmission gear 173 rotates CCW, the sun gear 175 rotates CW, and the planetary gears 178 and 179 revolve with CW rotation.

  As shown in FIG. 19, a transmission gear 180 and a transmission gear 181 are arranged adjacent to the planetary gear device 174. The transmission gear 180 is a two-stage gear in which a large-diameter gear 180L and a small-diameter gear 180S are coaxially and integrally configured. The planetary gears 178 and 179 of the planetary gear device 174 can be engaged with and disengaged from the gear 180L of the transmission gear 180. Further, the gear 180 </ b> S of the transmission gear 180 and the transmission gear 181 are meshed, and the transmission gear 181 is meshed with a driven gear 182 provided on the shaft of the guide flap 50.

  As shown in FIG. 19, the planetary gears 178 and 179 revolve by CW rotation, so that the planetary gear 178 meshes with the gear 180 </ b> L of the transmission gear 180. On the other hand, the planetary gear 179 is detached from the transmission gear 180. When the planetary gear 178 revolved by the CW rotation meshes with the transmission gear 180, the revolution of the planetary gears 178 and 179 is stopped. Then, the planetary gear 178 rotates by CCW rotation upon receiving the driving force transmitted from the sun gear 175. In response to this, the transmission gear 180 rotates CW. The transmission gear 181 meshing with the transmission gear 180 rotates CCW, and the driven gear 182 meshing with the transmission gear 181 rotates CW. By the CW rotation of the driven gear 182, the guide flap 50 is rotated so as to swing upward, and becomes the first position.

  As shown in FIG. 20, when the drive gear 69 rotates CCW, the transmission gear 173 rotates CW, the sun gear 175 rotates CCW, and the planetary gears 178 and 179 revolve around CCW rotation. As the planetary gears 178 and 179 revolve by CCW rotation, the planetary gear 179 meshes with the gear 180L of the transmission gear 180. On the other hand, the planetary gear 178 is detached from the transmission gear 180. When the planetary gear 179 revolved by the CCW rotation meshes with the transmission gear 180, the revolution of the planetary gears 178 and 179 is stopped. Then, the planetary gear 179 receives the driving force transmitted from the sun gear 175 and rotates by CW rotation. In response to this, the transmission gear 180 rotates CCW. The transmission gear 181 meshing with the transmission gear 180 rotates CW, and the driven gear 182 meshing with the transmission gear 181 rotates CCW. When the driven gear 182 rotates in the CCW direction, the guide flap 50 is rotated so as to swing downward, and becomes the second position.

  Although not shown in the drawing, a slip clutch is provided between the shaft provided with the driven gear 182 and the guide flap 50. The rotation of the shaft is transmitted to the guide flap 50 by the slip clutch. In the slip clutch, when a load of a predetermined torque or more is applied, the clutch plate slips and driving force transmission is cut off. As shown in FIG. 4, the guide flap 50 is swung between the first position and the second position, and is not rotated beyond each position by contacting the guide member or the like. So that it is regulated. Therefore, after the guide flap 50 reaches the first position or the second position, the rotation of the guide flap 50 is restricted so that the slip clutch slips, and the guide flap 50 is moved to the first position or the second position. The shaft provided with the driven gear 182 can be further rotated while being stationary at the position. The gear configuration from the transmission gear 180 to the driven gear 182 is not particularly limited, and the number and diameter of the transmission gears can be changed as appropriate according to the distance from the transmission gear 180 to each driven gear 182.

  Hereinafter, an image reading operation by the image reading apparatus 1 will be described. The image reading apparatus 1 can be used as an FBS or an ADF 3, but the use of the FBS is not particularly related to the present invention, and a detailed description thereof will be omitted. When the ADF 3 is used, the document cover 4 is closed with respect to the document table 2. Opening / closing of the document cover 4 is detected by a sensor or the like provided on the document table 2 and is controlled so that the ADF 3 can be used when the document cover 4 is closed. Then, n originals Gn to be read are placed on the paper feed tray 30. Here, the symbol Gn indicates a document, and the symbol n indicates the number of documents. Hereinafter, each document is represented as G1, G2,. The original Gn has a page with a smaller page number (i.e., the previous page) on the upper side and a page with a larger page number (i.e., next to the first side). ) Is placed on the paper feed tray 30 in a so-called face up so that the paper surface (hereinafter referred to as “second surface”) is on the lower side. The document Gn may be one sheet or a plurality of sheets, but in the present embodiment, it will be described as a plurality of sheets. For example, when reading images of a plurality of documents Gn of the same size, the plurality of documents Gn are overlapped so that the first surface of the first document G1 faces upward, that is, face-up. They are aligned and placed on the paper feed tray 30.

  When an instruction to start reading is input to the image reading apparatus 1, the motor 67 is driven, and the pickup roller 33, the separation roller 34, the transport rollers 35 </ b> A, 35 </ b> B, 35 </ b> C, 35 </ b> D, the paper discharge roller 36, and the reversible roller 43. It is rotationally driven at a predetermined timing. Further, the arm 29 is lowered and the pickup roller 33 comes into contact with the original G1 on the paper feed tray 30. Then, the sheets are separated one by one from the uppermost document G 1 that directly receives the rotational force of the pickup roller 33 and the separation roller 34, and sent to the document conveyance path 32. The fed document Gn is guided to the document conveyance path 32 and conveyed to the reading position, and the image reading unit 22 waiting under the reading position reads the image of the document Gn. Then, the document Gn after the image reading is discharged to the paper discharge tray 31. In such an image reading operation, the conveyance path of the original Gn differs depending on whether single-sided reading of the original Gn is performed or double-sided reading. Whether single-sided reading or double-sided reading of the document Gn is determined by a single-sided reading mode (single-sided mode) or a double-sided reading mode (double-sided mode) set in advance before the start of reading is input. The set single-sided reading mode or double-sided reading mode is stored in the RAM 63 of the control unit 60 as conveyance mode information. When the single-sided reading mode is set, the image reading apparatus 1 is operated so as to convey the original document along the conveyance path corresponding to the single-sided reading mode. When the double-sided reading mode is set, the double-sided reading mode is set. The image reading apparatus 1 is operated so as to convey the document along the corresponding conveyance path.

  Hereinafter, double-sided reading by the image reading apparatus 1 will be described with reference to FIGS. When the single-sided reading mode is set in the image reading apparatus 1, the original G1 fed from the paper feed tray 30 is conveyed through the original conveying path 32 with the first side facing the reading position, and the first reading mode is set. One side reading of only one side is performed, and then the paper is discharged to the paper discharge tray 31. Since such single-sided reading is not particularly relevant to the present invention, detailed description thereof is omitted. FIG. 21 is a flowchart for explaining the operation of the image reading apparatus 1 in the double-sided reading mode. FIG. 22 is a timing chart showing the operation timing of each component in the duplex reading mode. FIG. 23 is a diagram illustrating a state in which the separation roller 34 is idling. FIGS. 24 to 32 are schematic views showing the conveyance state of the document Gn in the duplex reading mode. In each figure, the surface indicated by “1” in the document Gn indicates the first surface, the surface indicated by “2” indicates the second surface, and these first surface, second surface, Is in a relation of front and back.

  Before the document Gn is fed, as shown in FIG. 24, the guide flap 50 continues the conveyance path at the first position, that is, the connection position 38 from the reading position side of the document conveyance path 32 to the discharge tray 31 side. It is in the position to do. The guide flap 46 is at a position where the conveyance path at the third position, that is, the intersection position 40 is continued from the paper feed tray 30 side to the reading position side of the document conveyance path 32, and the guide flap 47 is at the fifth position, that is, The conveyance path at the intersection position 40 is located at a position where it continues from the end 41 side of the two-way path 39 to the reading position side of the document conveyance path 32.

  When an instruction to start reading is input to the image reading apparatus 1 (S11 (Y)), it is determined by the first front sensor 52 whether or not the document Gn is placed on the paper feed tray 30 (S12). . When the control unit 60 determines that the document Gn is not placed on the paper feed tray 30 (S12 (N)), an error message “No document” is displayed on the display unit of the image reading apparatus 1 (S12). S13). If the document Gn is placed on the paper feed tray 30, the motor 67 is driven by CW rotation. A CW rotation command to the motor 67 is stored in the RAM 63 as rotation direction information. In the present embodiment, it is assumed that the motor 67 rotates CW at the start of reading. However, whether the motor 67 is rotated CW or CCW at the start of reading is arbitrary, and the rotation direction of the motor 67 is relative. Concept.

  The control unit 60 drives the motor 67 by CW rotation and turns on the solenoid 88 (see FIG. 22). At this time, as shown in FIGS. 7 and 8, the planetary gear device 75 of the first gear system 70 is unlocked by the locking mechanism 86, and the planetary gears 79, 80 are based on the rotation of the sun gear 76. Is revolved by CCW rotation to transmit the driving force to the transmission gear 94. As a result, the driven gear 95 rotates CW. As the driven gear 95 rotates CW, the driving force is transmitted to the arm 29 and the arm 29 is lowered. When the arm 29 is lowered, the pickup roller 33 comes into contact with the document G1 on the paper feed tray 30. Further, the CW rotation of the driven gear 95 is transmitted to the pickup roller 33 and the separation roller 34 by the second gear system 110, and the pickup roller 33 and the separation roller 34 rotate in the feeding direction, whereby the document G 1 is fed to the document conveyance path 32. It is carried to. When a plurality of documents Gn are placed on the sheet feeding tray 30, the document G2 directly below the document G1 may be double-fed along with the document G1 at the uppermost position. It is restrained by the provided friction pad. In this way, the document G1 is fed to the document transport path 32 (S14).

  In the document conveyance path 32, the driving force from the motor 67 is transmitted to the conveyance rollers 35 </ b> A, 35 </ b> B, 35 </ b> C, 35 </ b> D and the discharge roller 36 by the third gear system 120, and each roller is upstream in the conveyance direction of the document conveyance path 32. So that the original Gn is transported downstream from the transport direction, that is, in the transport direction. The original G1 fed from the paper feed tray 30 to the original conveying path 32 is nipped by the conveying roller 35A and the pinch roller 37 and is transmitted with a rotational force, whereby the original G1 is conveyed to the intersection position 40. . When the document G1 is fed to the document transport path 32 and the leading end of the document G1 in the transport direction is detected by the second front sensor 53, the second front sensor 53 is turned on (see FIG. 22).

  Since the guide flap 47 closes the transport path from the paper feed tray 30 side of the document transport path 32 to the intersecting position 40, the leading end of the document G 1 in the transport direction that has reached the intersecting position 40 comes into contact with the guide flap 47. Then, as shown in FIG. 25, the guide flap 47 changes from the fifth position to the sixth position, which is pushed by the leading edge of the document G1. As a result, the conveyance path from the paper feed tray 30 side to the reading position side of the document conveyance path 32 continues, and the conveyance path to the terminal end 41 side of the two-way path 39 is closed. Further, the conveyance path to the connection position 38 side of the two-way path 39 is closed by the guide flap 46. Therefore, the document G1 that has reached the intersection position 40 from the paper feed tray 30 side of the document transport path 32 is guided by the guide flap 46 and the guide flap 47 and does not enter any direction of the two-way path 39. The document is conveyed to the reading position side of the document conveyance path 32.

  The peripheral speeds of the transport rollers 35A, 35B, 35C, and 35D and the paper discharge roller 36 that are rotated by the driving force transmitted from the motor 67 by the third gear system 120 are as follows. 110 is set to be faster than the peripheral speed of the separating roller 34 that is rotated by the driving force transmitted by 110. As shown in FIG. 25, the original G1 fed from the paper feed tray 30 to the original conveyance path 32 is nipped and conveyed by the conveyance roller 35A and the pinch roller 37 while being pressed against the separation roller 34. As shown in FIG. 12, the separation roller 34 is allowed to idle for approximately one turn in the feeding direction by the one-turn clutch 112. Therefore, as shown in FIG. 23, the separation roller 34 that is in pressure contact with the original G1 is rotated by the original G1 conveyed at a predetermined speed by the conveying roller 35A and idles so as to advance in the feeding direction from the shaft 111. . As a result, a predetermined gap is formed in the transport direction between the first document G1 and the second document G2.

  The document G1 fed to the document transport path 32 is transported by the transport rollers 35A, 35B, and 35C so as to be reversed downward by the curved portion 32B of the document transport path 32, and reaches the first sheet sensor 54. To do. At this time, the leading edge of the document G1 in the conveyance direction is detected by the first sheet sensor 54, and the first sheet sensor 54 is turned on (see FIG. 22).

  When the original G1 is further conveyed and the rear end in the conveyance direction of the original G1 passes the second front sensor 53 as shown in FIG. 25, the rear end in the conveyance direction of the original G1 is detected by the second front sensor 53. That is, the second front sensor 53 is turned off (see FIG. 22). At this time, the control unit 60 switches the rotation of the motor 67 from CW rotation to CCW rotation based on the off signal of the second front sensor 53. In the present embodiment, since the separation roller 34 is allowed to idle for approximately one turn in the feeding direction by the one-turn clutch 112, a predetermined time T (see FIG. 5) after the second front sensor 53 is turned off. 22), the rotation of the motor 67 is switched from CW rotation to CCW rotation. Here, the time T is the time required until the separation roller 34 finishes idling and restarts rotation. More specifically, the separation roller 34 rotates again, and the leading end of the subsequent original G2 in the conveyance direction is nipped. It is set in advance to the time required for this. Note that, when the motor 67 is switched from CW rotation to CCW rotation, the leading end of the document G1 in the conveyance direction has reached the reading position, but at this point, image reading of the first surface of the document G1 is not performed. . In addition, when the rotation of the motor 67 is switched from CW rotation to CCW rotation, the leading end of the subsequent document G2 in the conveyance direction does not reach the intersection position 40.

  The separation roller 34 temporarily idles until the time T (see FIG. 22) elapses after the trailing end of the document G1 is detected by the second front sensor 53, but then rotates in the transport direction. As described above, the second front sensor 53 is provided on the downstream side in the transport direction of the separation roller 34. Therefore, until the time T elapses after detection of the trailing edge of the document G1 in the conveyance direction, the separation roller 34 feeds the next document G2 to the document conveyance path 32 (in the feeding operation of the present invention). Equivalent). That is, the separation roller 34 nips the leading end of the document G2 in the conveyance direction and performs an operation of taking out the document G2 from the paper feed tray 30. When the separation roller 34 nips the leading end of the document G2 in the conveyance direction, the time T elapses and the rotation of the motor 67 is switched from CW rotation to CCW rotation. When the rotation of the motor 67 is switched from CW rotation to CCW rotation, as shown in FIG. 10, the support arm 78 of the planetary gear device 75 is locked by the locking mechanism 86 and held in the disengaged position. Thereby, transmission of the driving force to the driven gear 95 is cut, and the shaft 111 that pivotally supports the separation roller 34 stops. Therefore, since the separation roller 34 does not rotate, the document G2 stops in a state where it is nipped between the separation roller 34 and the guide plate 19. The state in which the original G2 is nipped and stopped in this way is continued until the reading of both sides of the original G1 is completed. In other words, in the conveyance process of the original G1, only the period from when the feeding of the original G1 is started until the rotation of the motor 67 is switched from the CW rotation to the CCW rotation for the first time, the motor 67 supplies the separation roller 34. Driving force is transmitted.

  In the present embodiment, as described above, the one-round clutch 112 is provided on the shaft 111 of the second gear system 110, and a mechanism that idles the separation roller 34 when the document G1 passes through the separation roller 34 is employed. However, for example, when a mechanism that does not provide the one-round clutch 112 and does not cause the idling of the separation roller 34 is adopted, the rotation of the motor 67 is changed from the CW rotation when the second front sensor 53 is turned off. You may switch to CCW rotation. In this case, the separation roller 34 rotates in the conveyance direction until the second front sensor 53 on the downstream side in the conveyance direction of the separation roller 34 detects the trailing end of the document G1 in the conveyance direction. For this reason, the separation roller 34 scans the next document G2 after the trailing end of the document G1 in the conveyance direction passes through the nip point between the separation roller 34 and the guide plate 19 and is detected by the second front sensor 53. An operation of feeding the document to the document conveyance path 32 is performed.

  In order to switch the rotation of the motor 67 from CW rotation to CCW rotation, the CPU 61 of the control unit 60 first outputs a stop command to the motor 67 and then outputs a CCW rotation command. The history of the stop command and the CCW rotation command is stored in the RAM 63 as the rotation direction information together with the already output CW rotation command.

  On the other hand, as shown in FIGS. 13 to 15, the third gear system 120 is configured so that each of the transport rollers 35A, 35B, 35C, 35D and the discharge rollers 35A, 35B, 35D, A driving force in the conveying direction is transmitted to the paper roller 36. Therefore, as shown in FIGS. 25 and 26, even after the rotation of the motor 67 is switched, the document G1 is conveyed along the document conveyance path 32 toward the reading position by the conveyance roller 35B and the like. When the rotation of the motor 67 is switched, the stop command is output and the motor 67 is temporarily stopped. Thereafter, even immediately after the CCW rotation command is issued and the CCW rotation of the motor 67 is started, each of the transport rollers 35A and 35B is engaged until the planetary gear 126 is disengaged from the transmission gear 128 and meshes with the transmission gear 129. , 35C, 35D and the paper discharge roller 36, a gear loss (driving loss) occurs in which the driving force of the motor 67 is not transmitted. During this time, the motor 67 substantially idles. Due to this gear loss, the document G1 is temporarily stopped in the document transport path 32. If the original G1 is stopped during the image reading, the image quality is deteriorated. However, since the image reading is not started at this timing, the problem due to the gear loss does not occur.

  When the rotation of the motor 67 is switched from the CW rotation to the CCW rotation, the fourth gear system 150 causes the fifth gear system 151 to hold the planetary gear device 153 in the disengaged position and disconnect the driving force transmission to the driven gear 168. To do. Thereby, the reversible roller 43 stops (refer FIG. 22). The sixth gear system 170 changes the guide flap 50 to the second position (see FIG. 26) by switching the rotation of the motor 67 from CW rotation to CCW rotation. Note that the guide flap 47 returns from the sixth position to the fifth position when the trailing edge of the document G1 passes the intersection position 40.

  The document G1 is transported through the document transport path 32 with the first surface facing the reading position. When the original G1 is further conveyed and the leading end of the original G1 reaches the guide flap 50, the leading end of the original G1 is guided by the guide flap 50 as shown in FIG. Enter the two-way path 39. The second sheet sensor 55 detects the leading edge of the document G1 that has entered the two-way path 39 and is turned on (see FIG. 22). On the other hand, when the rear end of the document G1 passes through the first sheet sensor 54, the first sheet sensor 54 detects the rear end and is turned off (see FIG. 22). The on / off history of the second sheet sensor 55 is stored in the RAM 63 of the control unit 60 as reading state information. Upon receiving the second sheet sensor 55 being turned on, the control unit 60 turns on the solenoid 161 (see FIG. 22). As a result, when the document G1 is drawn into the two-way path 39, the support arm 156 of the planetary gear device 153 is released from the fifth gear system 151, and the motor 67 rotates CCW as shown in FIG. The planetary gear device 153 that has received the driving force transmission transmits the driving force of CW rotation to the driven gear 168, and the reversible roller 43 rotates in the retracting direction.

  Since the guide flap 46 closes the conveyance path from the two-way path 39 to the intersection position 40, the leading edge of the document G 1 that has entered the two-way path 39 contacts the guide flap 46 when reaching the intersection position 40. Touch. As shown in FIG. 27, the guide flap 46 rotates so as to be pushed up to the leading end of the document G1 conveyed through the two-way path 39, and changes from the third position to the fourth position. As a result, the conveyance path from the connection position 38 side of the two-way path 39 to the terminal end 41 side of the two-way path 39 continues, and the conveyance path to the reading position side of the document conveyance path 32 is closed. The guide flap 47 closes the conveyance path of the document conveyance path 32 toward the paper feed tray 30 side. Accordingly, the leading edge of the document G1 that has reached the crossing position 40 from the connection position 38 side of the two-way path 39 is guided by the guide flap 46 and the guide flap 47 and does not enter the document transport path 32, and thus the two-way path 39. It is conveyed to. The leading edge of the document G1 is nipped between the reversible roller 43 and the pinch roller 44, and the two-way path 39 is conveyed to the end 41 side by the rotation of the reversible roller 43 in the drawing direction.

  As shown in FIG. 28, after the trailing edge of the document G1 completely enters the end 41 side beyond the intersection position 40 of the two-way path 39, the control unit 60 changes the rotation of the motor 67 from CCW rotation to CW rotation. Switching (see FIG. 22). In order to switch the rotation of the motor 67 from CCW rotation to CW rotation, the CPU 61 of the controller 60 outputs a stop command to the motor 67 and then outputs a CW rotation command. The stop command and the CW rotation command are stored as rotation direction information in the RAM 63 together with a command already output for driving the motor 67.

  The second sheet sensor 55 detects the trailing edge of the document G1 conveyed through the two-way path 39 and is turned off. After a predetermined time has elapsed, the trailing edge of the document G1 passes through the intersection position 40. Therefore, the control unit 60 counts the detection signal of the second sheet sensor 55 and the conveyance distance or conveyance time by the conveyance roller 35D and the reversible roller 43. Accordingly, it is determined that the trailing edge of the document G1 has completely entered the end 41 side beyond the intersection position 40 of the two-way path 39. When the rotation of the motor 67 is switched, the document G1 that is nipped between the reversible roller 43 and the pinch roller 44 and protrudes from the terminal end 41 to the outside of the ADF 3 is returned to the intersection position 40.

  When a part of the document G1 protrudes from the end 41 of the bidirectional path 39 to the outside of the ADF 3, a part of the document G1 is supported by the document support part 42 (see FIG. 1). The leading edge of the document G1 overlaps with the document G2 on the paper feed tray 30. At this time, the alignment state of the originals on the paper feed tray 30 may be disturbed. However, as described above, the original plate G2 on the paper feed tray 30 has the guide plate 19 whose front end faces the separation roller 34. Therefore, the alignment state of the originals Gn on the paper feed tray 30 is not disturbed.

  When the document G1 passes through the intersection position 40 and moves away from the guide flap 46, the guide flap 46 rotates downward and returns to the third position.

  When the motor 67 is switched from CCW rotation to CW rotation, the planetary gear unit 153 of the fourth gear system 150 rotates the support arm 156 CW to drive the driving force of the motor 67 as shown in FIG. And the driven gear 168 is rotated CCW. Thereby, the reversible roller 43 rotates in the return direction. In response, the document G1 is switched back and conveyed so as to return to the intersection position 40 through the two-way path 39 (S15).

  On the other hand, as shown in FIGS. 13 to 15, the third gear system 120 is configured so that each of the transport rollers 35A, 35B, 35C, 35D and the discharge rollers 35A, 35B, 35D, A driving force is transmitted to the paper roller 36 so as to rotate in one direction. Accordingly, even after the rotation of the motor 67 is switched, the transport rollers 35A, 35B, 35C, and 35D and the paper discharge roller 36 rotate in one direction. When the motor 67 is switched from CCW rotation to CW rotation, the motor 67 idles until the planetary gear 126 is disengaged from the transmission gear 129 and meshes with the transmission gear 128, and the driving force of the motor 67 is changed to There is a gear loss that is not transmitted to the transport rollers 35A, 35B, 35C, 35D and the paper discharge roller 36.

  In the first gear system 70, when the rotation of the motor 67 is switched from CCW rotation to CW rotation, the locking mechanism 86 holds the planetary gear device 75 in the disengaged position and transmits the driving force to the driven gear 95. Disconnected. Thereafter, since the solenoid 88 is not operated, the planetary gear device 75 is held at the disengaged position even when the motor 67 is rotated in CW. Therefore, transmission of the rotational driving force to the separation roller 34 is continuously interrupted. The sixth gear system 170 changes the guide flap 50 to the first position by switching the rotation of the motor 67 from CCW rotation to CW rotation (see FIG. 29).

  The document G1 conveyed in the returning direction from the two-way path 39 comes into contact with the guide flap 46 at the third position at the intersection position 40. The guide flap 46 is restricted so as not to rotate downward from the third position. Accordingly, the conveyance path from the terminal end 41 side of the two-way path 39 to the reading position side of the document conveyance path 32 continues, and the conveyance path to the coupling position 38 side of the two-way path 39 is closed. Further, the guide flap 47 closes the conveyance path to the paper feed tray 30 side of the document conveyance path 32. Accordingly, as shown in FIG. 29, the document G1 is guided by the guide flap 46 and the guide flap 47, and does not enter the connection position 38 side of the two-way path 39 or the paper feed tray 30 side of the document transport path 32. Then, it is conveyed from the end 41 side of the two-way path 39 to the reading position side of the document conveying path 32. By returning the original G1 from the bidirectional path 39 to the upstream side of the reading position of the original conveyance path 32 in the conveyance direction, the leading edge and the rear end of the original G1 are reversed from the state where the original G1 was first conveyed in the original conveyance path 32. In this state, the document conveyance path 32 is retransmitted. In this way, the original G1 is switched back and conveyed.

  As described above, a path through which the document G1 fed from the sheet feeding tray 30 returns to the document transport path 32 on the upstream side in the transport direction of the reading position through the document transport path 32 and the two-way path 39 is the first of the present invention. Corresponds to the route.

  The leading end in the transport direction of the original G1 returned from the two-way path 39 to the upstream side in the transport direction of the reading position of the original transport path 32 is a predetermined position on the upstream side of the reading position in the transport direction. When reaching the switching position 45 immediately upstream, the rotation of the motor 67 is switched from CW rotation to CCW rotation. The control unit 60 determines whether the original G1 is switched back in the two-way path 39, that is, the elapsed time counted from the time when the rotation of the motor 67 is switched from CCW rotation to CW rotation, the rotation amount of the motor 67, or the like. The timing for switching the rotation of the motor 67 can be determined. The switching from the CW rotation to the CCW rotation is performed before the leading end of the document G1 in the conveyance direction reaches the reading position, that is, before the image reading unit 22 performs image reading at the reading position of the document G1.

  As shown in FIG. 30, the document G1 is conveyed so as to be turned downward by the curved portion 32B of the document conveyance path 32, and the first sheet sensor 54 detects the leading edge of the document G1 and is turned on (FIG. 22). reference). Since the leading edge of the document G1 reaches the reading position after a predetermined time has been detected by the first sheet sensor 54, if the leading edge of the document G1 reaches the reading position, the control unit 60 operates the image reading unit 22. Then, the image of the original G1 is read (S16, see FIG. 22). The original G1 passes through the reading position with the second side facing the image reading unit 22, and the image on the second side of the original G1 is read by the image reading unit 22. At this time, the control unit 60 continues to operate the image reading unit 22 until the trailing edge of the document G1 passes the reading position. When the original G1 is further conveyed and the rear end of the original G1 passes the first sheet sensor 54, the first sheet sensor 54 detects the rear end of the original G1 and turns off (see FIG. 22). The control unit 60 determines that the rear end in the conveyance direction of the document G1 has passed the reading position after the first sheet sensor 54 is turned off and a predetermined time has elapsed, and the second surface of the document G1 by the image reading unit 22 is determined. Is finished (see FIG. 22).

  The image data of the second side of the original G1 read by the image reading unit 22 is stored in a predetermined area of the RAM 63. The control unit 60 writes the image data in the RAM 63 and writes a variable indicating that the image reading of the second surface has been completed in a predetermined area of the RAM 63. This variable indicates “end of reading of second surface” and is used as reading state information.

  As shown in FIG. 31, when the leading edge of the document G1 reaches the switching position 45 on the upstream side in the transport direction of the reading position of the document transport path 32, the controller 60 rotates the motor 67 as described above. Switch from CW rotation to CCW rotation. At this time, a stop command and a CCW rotation command output from the CPU 61 of the control unit 60 are also stored in the RAM 63 as reading state information. In the third gear system 120, although the transmission of the driving force is temporarily interrupted by the gear loss when the rotation direction of the motor 67 is switched, the conveyance rollers 35A, 35B, 35C, and 35D are irrespective of the rotation direction of the motor 67. Since the driving force in the conveying direction is transmitted to the paper discharge roller 36, the original G1 is conveyed toward the reading position on the original conveying path 32 by the conveying roller 35B and the like even after the rotation of the motor 67 is switched.

  In the fourth gear system 150, when the rotation of the motor 67 is switched from CW rotation to CCW rotation, the support arm 156 of the planetary gear device 153 CCW rotates and is locked to the drive cutting mechanism 151. Thereby, the driving force transmission from the planetary gear device 153 to the driven gear 168 is cut off, and the reversible roller 43 stops. Therefore, as shown in FIG. 30, the rotation of the motor 67 is switched in a state where the leading end side of the document G1 is nipped by the conveyance roller 35B and the pinch roller 37 and the end side of the document G1 is nipped by the reversible roller 43 and the pinch roller 44. However, the reversible roller 43 does not rotate in the retracting direction. The reversible roller 43 from which the driving force transmission from the motor 67 is cut is rotated in the returning direction by the original G1 conveyed by the rotation of the conveying roller 35B.

  The first gear system 70 disengages the locking mechanism 86 from the planetary gear device 75. At this time, since the solenoid 88 is not operated, the planetary gear device 75 remains detached even when the motor 67 is rotated CCW. The sixth gear system 170 rotates the guide flap 50 to the second position by switching the rotation of the motor 67 from CW rotation to CCW rotation.

  When the document G1 is further transported and the second sheet sensor 55 detects the leading end of the document G1 entering the two-way path 39 and is turned on, the control unit 60 turns on the solenoid 161 (see FIG. 22). . As a result, when the document G1 is drawn into the two-way path 39, the support arm 156 of the planetary gear device 153 is released by the drive cutting mechanism 151, and the motor 67 rotates CCW as shown in FIG. Upon receiving the driving force transmission, the planetary gear device 153 transmits the driving force of CW rotation to the driven gear 168, and the reversible roller 43 rotates in the retracting direction.

  In the same manner as in FIG. 27, the leading end of the document G1 that has reached the intersection position 40 is pushed up to change from the third position to the fourth position so that the intersection position 40 is changed to the two-way path 39. Enter the end 41 side. In the same manner as in FIG. 28, after the trailing edge of the document G1 completely enters the end 41 side beyond the intersection position 40 of the two-way path 39, the control unit 60 changes the rotation of the motor 67 from CCW rotation to CW rotation. The rotation is switched, and the reversible roller 43 is rotated in the returning direction to return the document G1 to the intersection position 40. At this time, a stop command and a CW rotation command output from the CPU 61 of the control unit 60 are also stored in the RAM 63 as reading state information. 29, the original G1 returned from the two-way path 39 is guided by the guide flap 46 and the guide flap 47, and the reading position side of the original conveying path 32 from the end 41 side of the two-way path 39. It is conveyed to. As a result, the original G1 is retransmitted on the original conveyance path 32 in a state where the leading end and the rear end are reversed again, that is, in a state where the original is first fed to the original conveyance path 32 (S17).

  As described above, the path through which the original G1 returned from the two-way path 39 to the original transport path 32 returns to the upstream side in the transport direction of the reading position again through the original transport path 32 and the two-way path 39 is the first aspect of the present invention. This corresponds to two routes.

  In the third gear system 120, although the transmission of the driving force is temporarily interrupted by the gear loss when the rotation direction of the motor 67 is switched, the transport rollers 35A, 35B, 35C, Since the driving force in the transport direction is transmitted to 35D and the paper discharge roller 36, each of the transport rollers 35A, 35B, 35C, 35D and the paper discharge roller 36 rotates in the transport direction. The first gear system 70 is in a state in which the locking mechanism 86 holds the planetary gear device 75 at the disengaged position, and cuts off the driving force transmission to the driven gear 95. The sixth gear system 170 changes the guide flap 50 to the first position by switching the rotation of the motor 67 from CCW rotation to CW rotation.

  When the leading edge of the original G1 returned from the bidirectional path 39 to the upstream side of the reading position of the original conveying path 32 reaches the first sheet sensor 54 and is detected by the first sheet sensor 54, The one sheet sensor 54 is turned on (see FIG. 22). Since the leading end of the document G1 in the transport direction reaches the reading position after a predetermined time has been detected by the first sheet sensor 54, if the leading end of the document G1 in the transport direction reaches the reading position, the control unit 60 sets the image reading unit. 22 is operated to read the image of the original G1 (S18, see FIG. 22). In this case, the document G1 passes through the reading position with the first surface facing the image reading unit 22. The image reading unit 22 reads an image on the first surface of the document G1. When the original G1 is further conveyed and the rear end in the conveyance direction of the original G1 passes the first sheet sensor 54, a predetermined time elapses after the first sheet sensor 54 detects the rear end in the conveyance direction of the original G1 and turns off. After that, it is determined that the rear end of the document G1 in the transport direction has passed the reading position, and the control unit 60 ends the image reading of the first surface of the document G1 by the image reading unit 22 (see FIG. 22).

  The image data of the first surface of the original G1 read by the image reading unit 22 is stored in a predetermined area of the RAM 63. The control unit 60 writes the image data in the RAM 63 and writes a variable indicating that the image reading of the first surface is completed in a predetermined area of the RAM 63. This variable indicates “end of reading of first surface” and is used as reading state information.

  As shown in FIG. 32, the document G1 after the first surface is read is guided at the leading end in the conveyance direction to the discharge tray 31 side by the guide flap 50 at the connection position 38. Then, the paper is discharged onto the paper discharge tray 31 by the paper discharge roller 36 with the first surface facing down (S19).

  In this way, the path through which the original G1 returned from the two-way path 39 to the original transport path 32 is discharged to the paper discharge tray 31 through the original transport path 32 corresponds to the third path of the present invention.

  When the next original G2 is set on the paper feed tray 30 after the original G1 is discharged (S20 (Y)), that is, when the first front sensor 52 is on, the control unit 60 turns on the solenoid 88. Thus, the locking mechanism 86 releases the support arm 78 of the planetary gear device 75 and the first gear system 70 transmits the driving force from the motor 67 to the driven gear 95 to feed the separation roller 34. Rotate in the direction. As a result, the original G2 on the paper feed tray 30 is fed to the original conveyance path 32, and image reading on both sides of the original G2 is performed in the same manner as described above.

  Then, after discharging the last document Gn placed on the sheet feed tray 30 from the document transport path 32 to the sheet discharge tray 31, the control unit 60 switches the rotation of the motor 67 from CW rotation to CCW rotation, and solenoids. Turn on 88. As a result, as shown in FIG. 11, the driving force is transmitted from the planetary gear device 75, the driven gear 95 rotates CCW, and the shaft 111 rotates in the direction opposite to the feeding direction. The rotation of the shaft 111 is transmitted to the arm 29, and the arm 29 is raised so that the paper feed roller 33 is separated from the guide surface of the document conveyance path 32. As a result, the original Gn to be read next is returned to an initial state where it can be inserted beyond the lower side of the paper feed roller 33 until it contacts the separation roller 34. Thereafter, the control unit 60 stops the motor 67, and the image reading in the duplex reading mode is completed.

  As described above, in the process of transporting the document Gn through the first path, the image on the second surface of the document Gn is transported through the reading position without passing through the image reading of the document Gn and the document Gn is transported through the second path. In the duplex reading mode in which reading is performed and the image of the first surface of the document Gn is read in the process of transporting the document Gn in the third path, the rear end in the transport direction of the document G1 is the second front in the transport process of the first path. Since the rotation of the motor 67 is switched from the CW rotation to the CCW rotation when the time T (see FIG. 22) has elapsed since the detection by the sensor 53, the transmission of the driving force to the separation roller 34 is cut off. The document G2 stops in a state where the leading end side in the transport direction of the document G2 is pressed by the roller 34. Therefore, even when the leading edge of the document G1 protruding from the two-way path 39 comes into contact with the document G2 on the paper feed tray 30 during switchback conveyance, the placement state of the document G2 is maintained. Thus, after the original G1 is conveyed, the original G2 can be reliably and quickly fed to the original conveying path 32.

  In the image reading apparatus 1, a two-way path 39 for retransmitting the document Gn to the document transport path 32 extends from the connection position 38 on the downstream side in the transport direction of the scan position of the document transport path 32, thereby The two-way path 39 is merely an example, and the document conveying path 32 and the two-way path 39 according to the present invention are described in the above-described embodiment. Of course, the transfer route is not limited to this. Therefore, in the switchback conveyance in which the leading edge and the trailing edge of the document are reversed, the conveyance path of the bidirectional path can be appropriately changed as long as the document is temporarily exposed from the opening to the upper side of the paper feed tray 30. is there. Of course, the guide flap 46 and the guide flap 47 can be appropriately changed according to the conveyance path of the bidirectional path. For example, instead of the guide flaps 46 and 47, for example, an elastically deformable film may be adopted as the guide member. .

FIG. 1 is a perspective view showing an external configuration of an image reading apparatus 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the internal configuration of the image reading apparatus 1. FIG. 3 is an enlarged view showing the configuration of the intersection position 40. FIG. 4 is an enlarged view showing the configuration of the connection position 38. FIG. 5 is an enlarged view showing the configuration of the first front sensor 52. FIG. 6 is a block diagram illustrating a configuration of the control unit 60. FIG. 7 is a diagram showing a configuration of the first gear system 70. FIG. 8 is a diagram illustrating a configuration of the first gear system 70. FIG. 9 is a diagram illustrating the configuration of the planetary gear device 75 and the locking mechanism 86. FIG. 10 is a diagram illustrating a configuration of the first gear system 70. FIG. 11 is a diagram illustrating a configuration of the first gear system 70. FIG. 12 is a diagram illustrating a configuration of the second gear system 110. FIG. 13 is a diagram illustrating a configuration of the third gear system 120. FIG. 14 is a diagram illustrating a configuration of the third gear system 120. FIG. 15 is a diagram illustrating a configuration of the third gear system 120. FIG. 16 is a diagram illustrating a configuration of the fourth gear system 150. FIG. 17 is a diagram illustrating a configuration of the fourth gear system 150. FIG. 18 is a diagram illustrating a configuration of the fourth gear system 150. FIG. 19 is a diagram illustrating a configuration of the sixth gear system 170. FIG. 20 is a diagram illustrating a configuration of the sixth gear system 170. FIG. 21 is a flowchart for explaining the operation in the single-sided reading mode. FIG. 22 is a flowchart for explaining the operation in the duplex reading mode. FIG. 23 is a diagram illustrating a state where the separation roller 34 is idling. FIG. 24 is a schematic diagram illustrating an image reading operation in the single-sided reading mode. FIG. 25 is a schematic diagram illustrating an image reading operation in the single-sided reading mode. FIG. 26 is a schematic diagram illustrating an image reading operation in the single-sided reading mode. FIG. 27 is a schematic diagram showing an image reading operation in the duplex reading mode. FIG. 28 is a schematic diagram showing an image reading operation in the duplex reading mode. FIG. 29 is a schematic diagram showing an image reading operation in the duplex reading mode. FIG. 30 is a schematic diagram showing an image reading operation in the duplex reading mode. FIG. 31 is a schematic diagram showing an image reading operation in the duplex reading mode. FIG. 32 is a schematic diagram showing an image reading operation in the duplex reading mode. FIG. 33 is a schematic diagram showing document conveyance for double-sided reading by a conventional document conveyance device. FIG. 34 is a schematic diagram showing document conveyance for double-sided reading by a conventional document conveyance device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image reading apparatus 3 ... ADF (sheet conveyance apparatus)
19 ... Guide plate (plate, feeding means)
30 ... Paper feed tray (first tray)
31 ... Output tray (second tray)
32 ... Document transport path (sheet transport path, first transport path)
33 ... feed roller 34 ... separating roller (roller body, feeding means)
35A, 35B, 35C, 35D ... Conveying rollers (sheet conveying means, first conveying means)
36... Discharge roller (sheet conveying means, first conveying means)
37... Pinch roller (sheet conveying means, first conveying means)
38 ... Connection position (first position)
39 ... Two-way path (sheet conveyance path, second conveyance path)
43. Reversible roller (sheet conveying means, second conveying means)
44 ... Pinch roller (sheet conveying means, second conveying means)
45 ... switching position (second position)
50 ... Guide flap (guide means)
52... First front sensor 53... Second front sensor (first detection means)
54 ... 1st sheet sensor (2nd detection means)
55 ... 2nd sheet sensor (3rd detection means)
60... Control unit (control means)
61 ... CPU
62 ... ROM
63 ... RAM
67 ... Motor (drive source)

Claims (18)

A sheet conveying device for conveying a sheet member,
A first tray on which a plurality of sheet members before feeding are placed;
A second tray for placing a plurality of discharged sheet members;
An opening provided above the first tray;
A sheet conveying path that connects the first tray, the second tray, and the opening through a reading position;
A feeding means provided in the sheet conveyance path, and press-contacting the sheet member placed on the first tray, and sequentially feeding the sheet member to the sheet conveyance path;
Sheet conveying means provided in the sheet conveying path;
A drive source for rotationally driving in either the forward rotation direction or the reverse rotation direction;
Control means for switching the rotation direction of the drive source to either the normal rotation direction or the reverse rotation direction;
A rotational driving force according to the position of the sheet member in the sheet conveying path is transmitted from the driving source to the sheet conveying means, and when the driving source is driven in the forward rotation direction, the driving source rotates to the feeding means. A transmission means for transmitting a driving force, and interrupting the transmission of the rotational driving force from the driving source to the feeding means when the driving source is driven in the reverse rotation direction;
A first detection unit that is provided on the downstream side in the conveyance direction from the feeding unit in the sheet conveyance path and detects a rear end of the sheet member conveyed in the sheet conveyance path;
The control means includes
In the sheet conveying path, a sheet member fed from the first tray passes through the reading position, and then returns to the sheet conveying path on the upstream side in the conveying direction from the reading position, and the sheet conveying path. The returned sheet member passes through the reading position and the opening and returns to the sheet conveying path upstream in the conveying direction from the reading position, and the sheet member returned to the sheet conveying path again reads the reading. When a plurality of sheet members are conveyed from the first tray to the second tray sequentially through the position and the third path discharged to the second tray through the opening,
A sheet conveying apparatus that switches the drive source from a normal rotation direction to a reverse rotation direction based on a detection result of a rear end of the sheet member by the first detection unit when the sheet member is conveyed by the first path.   The control means switches the drive source from the normal rotation direction to the reverse rotation condition on the condition that the first detection means detects the rear end of the sheet member when conveying the sheet member along the first path. Item 2. The sheet conveying apparatus according to Item 1. The sheet conveying path includes a first conveying path from the first tray through the reading position to the second tray, and a second from the predetermined first position downstream of the reading position in the conveying direction to the opening. A conveyance path,
The sheet conveying apparatus according to claim 1, wherein the sheet conveying means includes a first conveying means provided in the first conveying path and a second conveying means provided in the second conveying path.   When the control unit conveys the sheet member along the second path, the leading end of the sheet member is downstream in the conveyance direction from the first detection unit, and is a predetermined second position upstream in the conveyance direction from the first position. The sheet conveying apparatus according to claim 3, wherein the driving source is switched from the normal rotation direction to the reverse rotation direction on the condition that the rotation angle has reached. The first detection means is provided in the first transport path,
A leading end and a trailing end of a sheet member that is provided on the downstream side in the transport direction from the first detection unit in the first transport path and on the upstream side in the transport direction from the reading position are detected. A second detecting means;
5. The sheet conveying apparatus according to claim 4, wherein the second position is downstream in the conveying direction from the first detecting unit and upstream in the conveying direction from the second detecting unit.   6. The sheet conveying apparatus according to claim 4, wherein, in the first conveying path, a section distance from the feeding unit to the second position is shorter than a minimum conveying direction length of a sheet member that can be conveyed on both sides by the apparatus.   The sheet according to any one of claims 1 to 6, wherein the feeding means includes a roller body that rotates by receiving the rotational driving force transmitted from the transmission means, and a plate that is pressed against the roller body. Conveying device.   The sheet conveying apparatus according to claim 1, wherein the first detection unit is provided in proximity to the feeding unit. The transmission means is
A first transmission mechanism for transmitting a rotational driving force in a fixed direction from the driving source to the first conveying means regardless of the rotational direction of the driving source;
In the process of transporting one sheet member placed on the first tray, the rotation direction of the drive source is first rotated forward by the control means from the feeding operation of feeding the sheet member to the sheet transport path. The sheet conveying apparatus according to claim 1, further comprising: a second transmission mechanism that transmits a rotational driving force from the driving source to the feeding unit only during a period from the direction to the reverse rotation direction. A rear end of a sheet member that is provided on the opening side from the first position in the second conveyance path and on the first position side from the second conveyance unit and that is conveyed on the second conveyance path is detected. Third detection means;
10. The sheet according to claim 3, further comprising a first driving force supply unit that supplies a rotational driving force for switchback conveyance of the sheet member in the second conveyance path to the second conveyance unit. 11. Conveying device.   The sheet conveying apparatus according to claim 10, wherein the rotation direction of the second conveying unit is switched to a direction corresponding to the rotation direction of the first drive supply unit controlled based on a detection result of the third detecting unit. The first driving force supply means includes the driving source and the transmission means.
The second transport unit is coupled to the transmission unit, and the rotation direction of the second transport unit is switched to a direction corresponding to the rotation direction of the drive source based on the detection result of the third detection unit. The sheet conveying apparatus according to 1.   The second transport means transports the sheet member in the second transport path in a direction to return the first transport path from the opening side to the first transport path when the drive source rotates in the forward rotation direction, and the drive source is reversed. The sheet conveying apparatus according to claim 12, wherein the sheet member in the second conveying path is conveyed toward the opening when rotating in the rotation direction. Guiding means that is rotatably supported at the first position and guides a sheet member conveyed along the first conveyance path to either the second conveyance path side or the second tray side;
The sheet conveying apparatus according to claim 3, further comprising a second driving force supply unit that supplies a rotational driving force to the guide unit.   The sheet conveying apparatus according to claim 14, wherein the rotation position of the guide unit is switched by the second driving force supply unit controlled according to the first path to the third path. The second driving force supply means includes the driving source and the transmission means,
The guide means is connected to the transmission means, guides the sheet member to the second tray side when the drive source rotates in the forward rotation direction, and seat member when the drive source rotates in the reverse rotation direction. The sheet conveying device according to claim 15, wherein the sheet conveying device guides the second sheet toward the second conveying path. A paper feed slot for feeding the sheet member;
A paper discharge port for discharging the sheet member;
A transport member for transporting a sheet member from the paper feed port to the paper discharge port;
A first path for guiding the sheet member while being conveyed from the sheet feeding port through the reading position to the end located above the sheet feeding port;
A second path for guiding the sheet member while being conveyed from the end to the end through the reading position;
A third path for guiding the sheet member while being conveyed from the terminal end to the discharge port through the reading position, and a sheet conveying apparatus comprising:
A reversible drive source,
A transmission member that rotates the transport unit according to the forward rotation of the drive source, and stops the rotation of the transport unit according to the reverse rotation of the drive source;
First detection means provided on the downstream side of the paper feed port in the first path;
And a control unit that switches the drive source from normal rotation to reverse rotation based on detection of the trailing edge of the sheet member in the first path. The reading position is equipped with an image reader,
18. The sheet conveying apparatus according to claim 17, wherein the document conveyed on the first path passes through a reading position without being read by the image reader.

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